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Steelmaning AI risk critiques

23 Stuart_Armstrong 23 July 2015 10:01AM

At some point soon, I'm going to attempt to steelman the position of those who reject the AI risk thesis, to see if it can be made solid. Here, I'm just asking if people can link to the most convincing arguments they've found against AI risk.

EDIT: Thanks for all the contribution! Keep them coming...

Self-improvement without self-modification

3 Stuart_Armstrong 23 July 2015 09:59AM

This is just a short note to point out that AIs can self-improve without having to self-modify. So locking down an agent from self-modification is not an effective safety measure.

How could AIs do that? The easiest and the most trivial is to create a subagent, and transfer their resources and abilities to it ("create a subagent" is a generic way to get around most restriction ideas).

Or it the AI remains unchanged and in charge, it could change the whole process around itself, so that the whole process changes and improves. For instance, if the AI is inconsistent and has to pay more attention to problems that are brought to its attention than problems that aren't, it can start to act to manage the news (or the news-bearers) to hear more of what it wants. If it can't experiment on humans, it will give advice that will cause more "natural experiments", and so on. It will gradually try to reform its environment to get around its programmed limitations.

Anyway, that was nothing new or deep, just a reminder point I hadn't seen written out.

 

Oracle AI: Human beliefs vs human values

3 Stuart_Armstrong 22 July 2015 11:54AM

It seems that if we can ever define the difference between human beliefs and values, we could program a safe Oracle by requiring it to maximise the accuracy of human beliefs on a question, while keeping human values fixed (or very little changing). Plus a whole load of other constraints, as usual, but that might work for a boxed Oracle answering a single question.

This is a reason to suspect it will not be easy to distinguish human beliefs and values ^_^

AI: requirements for pernicious policies

7 Stuart_Armstrong 17 July 2015 02:18PM

Some have argued that "tool AIs" are safe(r). Recently, Eric Drexler decomposed AIs into "problem solvers" (eg calculators), "advisors" (eg GPS route planners), and actors (autonomous agents). Both solvers and advisors can be seen as examples of tools.

People have argued that tool AIs are not safe. It's hard to imagine a calculator going berserk, no matter what its algorithm is, but it's not too hard to come up with clear examples of dangerous tools. This suggests the solvers vs advisors vs actors (or tools vs agents, or oracles vs agents) is not the right distinction.

Instead, I've been asking: how likely is the algorithm to implement a pernicious policy? If we model the AI as having an objective function (or utility function) and algorithm that implements it, a pernicious policy is one that scores high in the objective function but is not at all what is intended. A pernicious function could be harmless and entertaining or much more severe.

I will lay aside, for the moment, the issue of badly programmed algorithms (possibly containing its own objective sub-functions). In any case, to implement a pernicious function, we have to ask these questions about the algorithm:

  1. Do pernicious policies exist? Are there many?
  2. Can the AI find them?
  3. Can the AI test them?
  4. Would the AI choose to implement them?

The answer to 1. seems to be trivially yes. Even a calculator could, in theory, output a series of messages that socially hack us, blah, take over the world, blah, extinction, blah, calculator finishes its calculations. What is much more interesting is some types of agents have many more pernicious policies than others. This seems the big difference between actors and other designs. An actor AI in complete control of the USA or Russia's nuclear arsenal has all sort of pernicious policies easily to hand; an advisor or oracle has much fewer (generally going through social engineering), a tool typically even less. A lot of the physical protection measures are about reducing the number of sucessfull pernicious policies the AI has a cess to.

The answer to 2. is mainly a function of the power of the algorithm. A basic calculator will never find anything dangerous: its programming is simple and tight. But compare an agent with the same objective function and the ability to do an unrestricted policy search with vast resources... So it seems that the answer to 2. does not depend on any solver vs actor division, but purely on the algorithm used.

And now we come to the big question 3., whether the AI can test these policies. Even if the AI can find pernicious policies that rank high on its objective function, it will never implement them unless it can ascertain this fact. And there are several ways it could do so. Let's assume that a solver AI has a very complicated objective function - one that encodes many relevant facts about the real world. Now, the AI may not "care" about the real world, but it has a virtual version of that, in which it can virtually test all of its policies. With a detailed enough computing power, it can establish whether the pernicious policy would be effective at achieving its virtual goal. If this is a good approximation of how the pernicious policy would behave in the real world, we could have a problem.

But extremely detailed objective functions are unlikely. But even simple ones can show odd behaviour if the agents gets to interact repeatedly with the real world - this is the issue with reinforcement learning. Suppose that the agent attempts a translation job, and is rewarded on the accuracy of its translation. Depending on the details of what the AI knows and who choose the rewards, the AI could end up manipulating its controllers, similarly to this example. The problem is that one there is any interaction, all the complexity of humanity could potentially show up in the reward function, even if the objective function is simple.

Of course, some designs make this very unlikely - resetting the AI periodically can help to alleviate the problem, as can choosing more objective criteria for any rewards. Lastly on this point, we should mention the possibility that human R&D, by selecting and refining the objective function and the algorithm, could take the roll of testing the policies. This is likely to emerge only in cases where many AI designs are considered, and the best candiates are retained based on human judgement.

Finally we come to the question of whether the AI will implement the policy if it's found it and tested it. You could say that the point of FAI is to create an AI that doesn't choose to implement pernicious policies - but, more correctly, the point of FAI is to ensure that very few (or zero) pernicious policies exist in the first place, as they all score low on the utility function. However, there are a variety of more complicated designs - satisficers, agents using crude measures - where the questions of "Do pernicious policies exist?" and "Would the AI choose to implement them?" could become quite distinct.

 

Conclusion: a more through analysis of AI designs is needed

A calculator is safe, because it is a solver, it has a very simple objective function, with no holes in the algorithm, and it can neither find nor test any pernicious policies. It is the combination of these elements that makes it almost certainly safe. If we want to make the same claim about other designs, neither "it's just a solver" or "it's objective function is simple" would be enough; we need a careful analysis.

Though, as usual, "it's not certainly safe" is a quite distinct claim from "it's (likely) dangerous", and they should not be conflated.

Examples of AI's behaving badly

21 Stuart_Armstrong 16 July 2015 10:01AM

Some past examples to motivate thought on how AI's could misbehave:

An algorithm pauses the game to never lose at Tetris.

In "Learning to Drive a Bicycle using Reinforcement Learning and Shaping", Randlov and Alstrom, describes a system that learns to ride a simulated bicycle to a particular location. To speed up learning, they provided positive rewards whenever the agent made progress towards the goal. The agent learned to ride in tiny circles near the start state because no penalty was incurred from riding away from the goal.

A similar problem occurred with a soccer-playing robot being trained by David Andre and Astro Teller (personal communication to Stuart Russell). Because possession in soccer is important, they provided a reward for touching the ball. The agent learned a policy whereby it remained next to the ball and “vibrated,” touching the ball as frequently as possible. 

Algorithms claiming credit in Eurisko: Sometimes a "mutant" heuristic appears that does little more than continually cause itself to be triggered, creating within the program an infinite loop. During one run, Lenat noticed that the number in the Worth slot of one newly discovered heuristic kept rising, indicating that had made a particularly valuable find. As it turned out the heuristic performed no useful function. It simply examined the pool of new concepts, located those with the highest Worth values, and inserted its name in their My Creator slots.

The AI, the best human advisor

7 Stuart_Armstrong 13 July 2015 03:33PM

A putative new idea for AI control; index here.

All my ideas on reduced impact AI follow the same format: some restriction to ensure a reduced impact (I generally use something like "could a future AI detect this one existed"?) and some "trick" to allow a way of still achieving a larger impact. Further more, there is always a "nice" way of achieving this larger impact (do the thing we really want you to do, and only that!), so that we hope the AI can be forced into that behaviour. Examples of "tricks" are:

In this post, I'll present another variant - one that I think is the most interesting so far. I won't change the reduced impact condition, but will present a different "trick".

 

AI pretends to be human

As in this post, imagine that we have a reduced-impact AI in a box that conceals it from us. The AI has some goal, and will output some data to further that goal, then turn itself off. And then we'll shake the box around or something, so we can't be sure that the AI was turned on.

There are two issues to deal with, here: a) The message itself is strong evidence that the AI was turned on, and b) if we exclude the message from the reduced impact, the message becomes dangerous.

To deal with a), first of all. This approach gets much easier if we have a whole brain emulation (WBE). Then we can house the WBE in the box with the AI. If the AI doesn't send out a message, then the WBE sends out is own message instead. There are variants we can try here if we don't have WBE - maybe some human volunteer willing to either die or take amnesia pills at the end of the experiment.

So, receiving a coherent message is not a surprising thing to come out the output channel. However, an AI motivated strongly by reduced impact, will simply seek to imitate as precisely as possible what the WBE would send. We still need a trick to get something useful.

 

AI pretends to be BEST human

Imagine that we wanted the AI to give us investment advice to make us rich. Say, a binary task: get us ten million dollars over the course of the year.

Now, this is the kind of thing that the WBE could conceivably achieve. We could run the WBE fast, for three subjective weeks, and it has a chance of giving us advice that would get us that rich. Assume that it only has 0.1% chance of doing so. The AI, on the other hand, could produce advice that makes us that rich with almost certainty.

Therefore if we get advice, follow it, and end up at least ten million dollars richer, we can conclude that the odds update of the AI having given us the advice (rather than the WBE doing so) is about 1:1000.

And this gives us the solution to b). The "trick", the escape clause, is by conditioning on the outcome of our investments. So we're asking: given that we have become rich (and given the other facts about the universe in 50 years time) what additional evidence is there that the AI was turned on?

Now, a sensible WBE is almost certain to not come up with a scheme that destroys the universe with self-tiling agents - or, indeed, does anything too crazy. We could instruct the WBE to this effect, and we're only running it for three weeks, which prevents the kind of drifts that you see in more extreme situations. Thus a message from the WBE, no matter how likely it is to make us rich, is almost certain to not lead to tilling the universe with self-replicating nano-bots.

So here, the AI merely has to come up with a message that could have come from the WBE, with at least 0.01% probability, and that would indeed make us rich. And, therefore, the message cannot contain secret code that would optimise the universe.

Note that we need that the goal we are looking for be not too extreme in impact (the higher the impact of the goal, the more latitude the AI has to have impact itself, "hiding" inside the goal's impact), and we should restrict to event of probability, say, greater than 1/10,000 (as when the probability gets too small, odd events start happening).

It seems that this scheme could result in AIs that always give the very best possible advice a human (or WBE) could ever give, which would be a very useful result.

 

Whose probability?

We have a probability distribution over events. The AI itself will have a probability distribution over events. The future hypothetical super-super-AI it is using to compute reduced impact has a probability distribution over events - and the AI has a probability distribution over that probability distribution. If all of them agree on the probability of us getting richer (given WBE advice and given not), then this scheme should work.

If they disagree, there might be problems. A more complex approach could directly take into account the divergent probability estimates; I'll think of that and return to the issue later.

Moral AI: Options

9 Manfred 11 July 2015 09:46PM

Epistemic status: One part quotes (informative, accurate), one part speculation (not so accurate).

One avenue towards AI safety is the construction of "moral AI" that is good at solving the problem of human preferences and values. Five FLI grants have recently been funded that pursue different lines of research on this problem.

The projects, in alphabetical order:

Most contemporary AI systems base their decisions solely on consequences, whereas humans also consider other morally relevant factors, including rights (such as privacy), roles (such as in families), past actions (such as promises), motives and intentions, and so on. Our goal is to build these additional morally relevant features into an AI system. We will identify morally relevant features by reviewing theories in moral philosophy, conducting surveys in moral psychology, and using machine learning to locate factors that affect human moral judgments. We will use and extend game theory and social choice theory to determine how to make these features more precise, how to weigh conflicting features against each other, and how to build these features into an AI system. We hope that eventually this work will lead to highly advanced AI systems that are capable of making moral judgments and acting on them.

Techniques: Top-down design, game theory, moral philosophy

Previous work in economics and AI has developed mathematical models of preferences, along with algorithms for inferring preferences from observed actions. [Citation of inverse reinforcement learning] We would like to use such algorithms to enable AI systems to learn human preferences from observed actions. However, these algorithms typically assume that agents take actions that maximize expected utility given their preferences. This assumption of optimality is false for humans in real-world domains. Optimal sequential planning is intractable in complex environments and humans perform very rough approximations. Humans often don't know the causal structure of their environment (in contrast to MDP models). Humans are also subject to dynamic inconsistencies, as observed in procrastination, addiction and in impulsive behavior. Our project seeks to develop algorithms that learn human preferences from data despite the suboptimality of humans and the behavioral biases that influence human choice. We will test our algorithms on real-world data and compare their inferences to people's own judgments about their preferences. We will also investigate the theoretical question of whether this approach could enable an AI to learn the entirety of human values.

Techniques: Trying to find something better than inverse reinforcement learning, supervised learning from preference judgments

The future will see autonomous agents acting in the same environment as humans, in areas as diverse as driving, assistive technology, and health care. In this scenario, collective decision making will be the norm. We will study the embedding of safety constraints, moral values, and ethical principles in agents, within the context of hybrid human/agents collective decision making. We will do that by adapting current logic-based modelling and reasoning frameworks, such as soft constraints, CP-nets, and constraint-based scheduling under uncertainty. For ethical principles, we will use constraints specifying the basic ethical ``laws'', plus sophisticated prioritised and possibly context-dependent constraints over possible actions, equipped with a conflict resolution engine. To avoid reckless behavior in the face of uncertainty, we will bound the risk of violating these ethical laws. We will also replace preference aggregation with an appropriately developed constraint/value/ethics/preference fusion, an operation designed to ensure that agents' preferences are consistent with the system's safety constraints, the agents' moral values, and the ethical principles of both individual agents and the collective decision making system. We will also develop approaches to learn ethical principles for artificial intelligent agents, as well as predict possible ethical violations.

Techniques: Top-down design, obeying ethical principles/laws, learning ethical principles

The objectives of the proposed research are (1) to create a mathematical framework in which fundamental questions of value alignment can be investigated; (2) to develop and experiment with methods for aligning the values of a machine (whether explicitly or implicitly represented) with those of humans; (3) to understand the relationships among the degree of value alignment, the decision-making capability of the machine, and the potential loss to the human; and (4) to understand in particular the implications of the computational limitations of humans and machines for value alignment. The core of our technical approach will be a cooperative, game-theoretic extension of inverse reinforcement learning, allowing for the different action spaces of humans and machines and the varying motivations of humans; the concepts of rational metareasoning and bounded optimality will inform our investigation of the effects of computational limitations.

Techniques: Trying to find something better than inverse reinforcement learning (differently this time), creating a mathematical framework, whatever rational metareasoning is

Autonomous AI systems will need to understand human values in order to respect them. This requires having similar concepts as humans do. We will research whether AI systems can be made to learn their concepts in the same way as humans learn theirs. Both human concepts and the representations of deep learning models seem to involve a hierarchical structure, among other similarities. For this reason, we will attempt to apply existing deep learning methodologies for learning what we call moral concepts, concepts through which moral values are defined. In addition, we will investigate the extent to which reinforcement learning affects the development of our concepts and values.

Techniques: Trying to identify learned moral concepts, unsupervised learning 

 

The elephant in the room is that making judgments that always respect human preferences is nearly FAI-complete. Application of human ethics is dependent on human preferences in general, which are dependent on a model of the world and how actions impact it. Calling an action ethical also can also depend on the space of possible actions, requiring a good judgment-maker to be capable of search for good actions. Any "moral AI" we build with our current understanding is going to have to be limited and/or unsatisfactory.

Limitations might be things like judging which of two actions is "more correct" rather than finding correct actions, only taking input in terms of one paragraph-worth of words, or only producing good outputs for situations similar to some combination of trained situations.

Two of the proposals are centered on top-down construction of a system for making ethical judgments. Designing a system by hand, it's nigh-impossible to capture the subtleties of human values. Relatedly, it seems weak at generalization to novel situations, unless the specific sort of generalization has been forseen and covered. The good points of a top down approach are that it can capture things that are important, but are only a small part of the description, or are not easily identified by statistical properties. A top-down model of ethics might be used as a fail-safe, sometimes noticing when something undesirable is happening, or as a starting point for a richer learned model of human preferences.

Other proposals are inspired by inverse reinforcement learning. Inverse reinforcement learning seems like the sort of thing we want - it observes actions and infers preferences - but it's very limited. The problem of having to know a very good model of the world in order to be good at human preferences rears its head here. There are also likely unforseen technical problems in ensuring that the thing it learns is actually human preferences (rather than human foibles, or irrelevant patterns) - though this is, in part, why this research should be carried out now.

Some proposals want to take advantage of learning using neural networks, trained on peoples' actions or judgments. This sort of approach is very good at discovering patterns, but not so good at treating patterns as a consequence of underlying structure. Such a learner might be useful as a heuristic, or as a way to fill in a more complicated, specialized architecture. For this approach like the others, it seems important to make the most progress toward learning human values in a way that doesn't require a very good model of the world.

Presidents, asteroids, natural categories, and reduced impact

1 Stuart_Armstrong 06 July 2015 05:44PM

A putative new idea for AI control; index here.

EDIT: I feel this post is unclear, and will need to be redone again soon.

This post attempts to use the ideas developed about natural categories in order to get high impact from reduced impact AIs.

 

Extending niceness/reduced impact

I recently presented the problem of extending AI "niceness" given some fact X, to niceness given ¬X, choosing X to be something pretty significant but not overwhelmingly so - the death of a president. By assumption we had a successfully programmed niceness, but no good definition (this was meant to be "reduced impact" in a slight disguise).

This problem turned out to be much harder than expected. It seems that the only way to do so is to require the AI to define values dependent on a set of various (boolean) random variables Zj that did not include X/¬X. Then as long as the the random variables represented natural categories, given X, the niceness should extend.

What did we mean by natural categories? Informally, it means that X should not appear in the definitions of these random variables. For instance, nuclear war is a natural category; "nuclear war XOR X" is not. Actually defining this was quite subtle; diverting through the grue and bleen problem, it seems that we had to define how we update X and the Zj given the evidence we expected to find. This was put in equation as picking Zj's that minimize

  • Variance{log[ P(X∧Z|E)*P(¬X∧¬Z|E) / P(X∧¬Z|E)*P(¬X∧Z|E) ]} 

where E is the random variable denoting the evidence we expected to find. Note that if we interchange X and ¬X, the ratio inverts, the log changes sign - but this makes no difference to the variance. So we can equally well talk about extending niceness given X to ¬X, or niceness given ¬X to X.

 

Perfect and imperfect extensions

The above definition would work for an "perfectly nice AI". That could be an AI that would be nice, given any combination of estimates of X and Zj. In practice, because we can't consider every edge case, we would only have an "expectedly nice AI". That means that the AI can fail to be nice in certain unusual and unlikely edge cases, in certain strange set of values of Zj that almost never come up...

...or at least, that almost never come up, given X. Since the "expected niceness" was calibrated given X, the such an expectedly nice AI may fail to be nice if ¬X results in a substantial change in the probability of the Zj (see the second failure mode in this post; some of the Zj may be so tightly coupled to the value of X that an expected niceness AI considers them fixed, and this results in problems if ¬X happens and their values change).

One way of fixing this is to require that the "swing" of the Zj be small upon changing X to ¬X or vice versa. Something like, for all values of {aj}, the the ratio P({Zj=aj} | X) / P({Zj=aj} | ¬X) is contained between 100 and 1/100. This means that a reasonably good "expected niceness" calibrated on the Zj will transfer from X to ¬X (though the error may grow). This approach has some other advantages, as we'll see in the next section.

Of course, problems arise if the Zj are defined by smashing together events relatively independent of X with some that are very strongly dependent on X, into the same variable. Thus we'll further require that Zj cannot be decomposed into natural subvariables whose values swing more under changes from X to ¬X.

 

High impact from reduced impact

With this, we are finally in a position to define a reduced impact AI design that can have a large impact. Imagine that an asteroid is coming to hit the Earth. Two AIs are charged with targeting a laser at it. The laser isn't perfectly effective, and the asteroid isn't perfectly certain to hit the Earth anyway: let's say aiming the laser correctly will reduce the odds of impact by a factor of 10 or so (well within the probability swing restrictions of the previous section).

In the original formulation of this, the AIs were tasked with outputting the x and y coordinates to aim the laser. Here, instead, they'll be tasked with constructing the motivation of a robotic subagent that will move around for a while, see things and interact, before physically aiming the laser in the right direction. This task is harder.

Then the top level AI charged with aiming the y coordinates is given the following task:

  • It is motivated to cause the the correct y-coordinate to be outputted.
  • If the x-coordinate AI is not turned on (call this event ¬X), it is strongly motivated to have reduced impact.
  • It must phrase the robotic subagent's utility function in terms of the Zj that obey all the properties above.
  • The evidence E considered for the equation governing the naturalness of Zj is considered (for example) to be a random sampling of space at the time both AIs are turned on. Most importantly, this is defined to be a theoretical process that the AI cannot affect physically.

So what will the AI do? It will produce a robot that will aim to aim the the y-coordinate of the laser correctly, given ¬X, and not expand dangerously. However, we've setup things so that X is virtually certain, so the robot will see another, x-aiming robot, wander around. The chances of this happening, given ¬X, are minuscule, so the swing of the probability from ¬X to X, is huge. So, by the restrictions we've put on the Zj, the robot will not be motivated to change its behaviour just because its sees the other robot.

And if the laser is fired, the impact on humanity will, conversely, not be that large, so well within the parameters of the Zj. Thus the "general reduced impact" portion of the robot's motivation will be preserved.

And, of course, the x-robot will have the mirror image motivations, so they will both aim correctly, it seems. This should evade the problem described here.

 

Failure modes

There are two ways the approach could fail: one bad way, and two graceful ways. The bad way is if the "no decomposition" requirements (one of them is presented above, the other is in this post) fail. In this case, the niceness or reduced impact are not guaranteed to be extended to ¬X, and the AI's behaviour can become undefined. Note that this is is not bad optimisation pressure, just an absence of optimisation pressure - but that could still be potentially dangerous.

The first graceful failure happens if the AI is not able to create a reduced impact sub-agent given the restrictions on the Zj above. In that case, the AI does nothing. The second graceful failure happens if the AI evades our attempts to increase its impact, given ¬X. In that case, it simply becomes a reduced impact AI that does little. Not ideal, but not deadly.

 

Overall status: I'm not sure the idea is sound, at least not yet. Critiques welcome.

Grue, Bleen, and natural categories

3 Stuart_Armstrong 06 July 2015 01:47PM

A putative new idea for AI control; index here.

In a previous post, I looked at unnatural concepts such as grue (green if X was true, blue if it was false) and bleen. This was to enable one to construct the natural categories that extend AI behaviour, something that seemed surprisingly difficult to do.

The basic idea discussed in the grue post was that the naturalness of grue and bleen seemed dependent on features of our universe - mostly, that it was easy to tell whether an object was "currently green" without knowing what time it was, but we could not know whether the object was "currently grue" without knowing the time.

So the naturalness of the category depended on the type of evidence we expected to find. Furthermore, it seemed easier to discuss whether a category is natural "given X", rather than whether that category is natural in general. However, we know the relevant X in the AI problems considered so far, so this is not a problem.

 

Natural category, probability flows

Fix a boolean random variable X, and assume we want to check whether the boolean random variable Z is a natural category, given X.

If Z is natural (for instance, it could be the colour of an object, while X might be the brightness), then we expect to uncover two types of evidence:

  • those that change our estimate of X; this causes probability to "flow" as follows (or in the opposite directions):

  • ...and those that change our estimate of Z:

Or we might discover something that changes our estimates of X and Z simultaneously. If the probability flows to X and and Z in the same proportions, we might get:

What is an example of an unnatural category? Well, if Z is some sort of grue/bleen-like object given X, then we can have Z = X XOR Z', for Z' actually a natural category. This sets up the following probability flows, which we would not want to see:

More generally, Z might be constructed so that X∧Z, X∧¬Z, ¬X∧Z and ¬X∧¬Z are completely distinct categories; in that case, there are more forbidden probability flows:

and

In fact, there are only really three "linearly independent" probability flows, as we shall see.

 

Less pictures, more math

Let's represent the four possible state of affairs by four weights (not probabilities):

Since everything is easier when it's linear, let's set w11 = log(P(X∧Z)) and similarly for the other weights (we neglect cases where some events have zero probability). Weights are correspond to the same probabilities iff you get from one set to another by multiplying by a strictly positive number. For logarithms, this corresponds to adding the same constant to all the log-weights. So we can normalise our log-weights (select a single set of representative log-weights for each possible probability sets) by choosing the w such that

w11 + w12 + w21 + w22 = 0.

Thus the probability "flows" correspond to adding together two such normalised 2x2 matrices, one for the prior and one for the update. Composing two flows means adding two change matrices to the prior.

Four variables, one constraint: the set of possible log-weights is three dimensional. We know we have two allowable probability flows, given naturalness: those caused by changes to P(X), independent of P(Z), and vice versa. Thus we are looking for a single extra constraint to keep Z natural given X.

A little thought reveals that we want to keep constant the quantity:

w11 + w22 - w12 - w21.

This preserves all the allowed probability flows and rules out all the forbidden ones. Translating this back to a the general case, let "e" be the evidence we find. Then if Z is a natural category given X and the evidence e, the following quantity is the same for all possible values of e:

log[P(X∧Z|e)*P(¬X∧¬Z|e) / P(X∧¬Z|e)*P(¬X∧Z|e)].

If E is a random variable representing the possible values of e, this means that we want

log[P(X∧Z|E)*P(¬X∧¬Z|E) / P(X∧¬Z|E)*P(¬X∧Z|E)]

to be constant, or, equivalently, seeing the posterior probabilities as random variables dependent on E:

  • Variance{log[ P(X∧Z|E)*P(¬X∧¬Z|E) / P(X∧¬Z|E)*P(¬X∧Z|E) ]} = 0.

Call that variance the XE-naturalness measure. If it is zero, then Z defines a XE-natural category. Note that this does not imply that Z and X are independent, or independent conditional on E. Just that they are, in some sense, "equally (in)dependent whatever E is".

 

Almost natural category

The advantage of that last formulation becomes visible when we consider that the evidence which we uncover is not, in the real world, going to perfectly mark Z as natural, given X. To return to the grue example, though most evidence we uncover about an object is going to be the colour or the time rather than some weird combination, there is going to be somebidy who will right things like "either the object is green, and the sun has not yet set in the west; or instead perchance, those two statements are both alike in falsity". Upon reading that evidence, if we believe it in the slightest, the variance can no longer be zero.

Thus we cannot expect that the above XE-naturalness be perfectly zero, but we can demand that it be low. How low? There seems no principled way of deciding this, but we can make one attempt: that we cannot lower it be decomposing Z.

What do we mean by that? Well, assume that Z is a natural category, given X and the expected evidence, but Z' is not. Then we can define a new category boolean Y to be Z with high probability, and Z' otherwise. This will still have low XE-naturalness measure (as Z does) but is obviously not ideal.

Reversing this idea, we say Z defines a "XE-almost natural category" if there is no "more XE-natural" category that extends X∧Z (and the other for conjunctions). Technically, if

X∧Z = X∧Y,

Then Y must have equal or greater XE-naturalness measure to Z. And similarly for X∧¬Z, ¬X∧Z, and ¬X∧¬Z.

Note: I am somewhat unsure about this last definition; the concept I want to capture is clear (Z is not the combination of more XE-natural subvariables), but I'm not certain the definition does it.

 

Beyond boolean

What if Z takes n values, rather than being a boolean? This can be treated simply.

If we set the wjk to be log-weights as before, there are 2n free variables. The normalisation constraint is that they all sum to a constant. The "permissible" probability flows are given by flows from X to ¬X (adding a constant to the first column, subtracting it from the second) and pure changes in Z (adding constants to various rows, summing to 0). There are 1+ (n-1) linearly independent ways of doing this.

Therefore we are looking for 2n-1 -(1+(n-1))=n-1 independent constraints to forbid non-natural updating of X and Z. One basis set for these constraints could be to keep constant the values of

wj1 + w(j+1)2 - wj2 - w(j+1)1,

where j ranges between 1 and n-1.

This translates to variance constraints of the type:

  • Variance{log[ P(X∧{Z=j}|E)*P(¬X∧{Z=j+1}|E) / P(X∧{Z=j+1}|E)*P(¬X∧{Z=j}|E) ]} = 0.

But those are n different possible variances. What is the best global measure of XE-naturalness? It seems it could simply be

  • Maxjk Variance{log[ P(X∧{Z=j}|E)*P(¬X∧{Z=k}|E) / P(X∧{Z=k}|E)*P(¬X∧{Z=j}|E) ]} = 0.

If this quantity is zero, it naturally sends all variances to zero, and, when not zero, is a good candidate for the degree of XE-naturalness of Z.

The extension to the case where X takes multiple values is straightforward:

  • Maxjklm Variance{log[ P({X=l}∧{Z=j}|E)*P({X=m}∧{Z=k}|E) / P({X=l}∧{Z=k}|E)*P({X=m}∧{Z=j}|E) ]} = 0.

Note: if ever we need to compare the XE-naturalness of random variables taking different numbers of values, it may become necessary to divide these quantities by the number of variables involved, or maybe substitute a more complicated expression that contains all the different possible variances, rather than simply the maximum.

 

And in practice?

In the next post, I'll look at using this in practice for an AI, to evade presidential deaths and deflect asteroids.

Green Emeralds, Grue Diamonds

8 Stuart_Armstrong 06 July 2015 11:27AM

A putative new idea for AI control; index here.

When posing his "New Riddle of Induction", Goodman introduced the concepts of "grue" and "bleen" to show some of the problems with the conventional understanding of induction.

I've somewhat modified those concepts. Let T be a set of intervals in time, and we'll use the boolean X to designate the fact that the current time t belongs to T (with ¬X equivalent to t∉T). We'll define an object to be:

  • Grue if it is green given X (ie whenever t∈T), and blue given ¬X (ie whenever t∈T).
  • Bleen if it is blue given X, and green given ¬X.

At this point, people are tempted to point out the ridiculousness of the concepts, dismissing them because of their strange disjunctive definitions. However, this doesn't really solve the problem; if we take grue and bleen as fundamental concepts, then we have the disjunctively defined green and blue; an object is:

  • Green if it is grue given X, and bleen given ¬X.
  • Blue if it is bleen given X, and grue given ¬X.

Still, the categories green and blue are clearly more fundamental than grue and bleen. There must be something we can whack them with to get this - maybe Kolmogorov complexity or stuff like that? Sure someone on Earth could make a grue or bleen object (a screen with a timer, maybe?), but it would be completely artificial. Note that though grue and bleen are unnatural, "currently grue" (colour=green XOR ¬X) or "currently bleen" (colour=blue XOR ¬X) make perfect sense (though they require knowing X, an important point for later on).

But before that... are we so sure the grue and bleen categories are unnatural? Relative to what?

 

Welcome to Chiron Beta Prime

Chiron Beta Prime, apart from having its own issues with low-intelligence AIs, is noted for having many suns: one large sun that glows mainly in the blue spectrum, and multiple smaller ones glowing mainly in the green spectrum. They all emit in the totality of the spectrum, but they are stronger in those colours.

Because of the way the orbits are locked to each other, the green suns are always visible from everywhere. The blue sun rises and sets on a regular schedule; define T to be time when the blue sun is risen (so X="Blue sun visible, some green suns visible" and ¬X="Blue sun not visible, some green suns visible").

Now "green" is a well defined concept in this world. Emeralds are green; they glow green under the green suns, and do the same when the blue sun is risen. "Blue" is also a well-defined concept. Sapphires are blue. They glow blue under the blue sun and continue to do so (albeit less intensely) when it is set.

But "grue" is also a well defined concept. Diamonds are grue. They glow green when the green suns are the only ones visible, but glow blue under the glare of the blue sun.

Green, blue, and grue (which we would insist on calling green, blue and white) are thus well understood and fundamental concepts, that people of this world use regularly to compactly convey useful information to each other. They match up easily to fundamental properties of the objects in question (eg frequency of light reflected).

Bleen, on the other hand - don't be ridiculous. Sure, someone on Chiron Beta Prime could make a bleen object (a screen with a timer, maybe?), but it would be completely artificial.

In contrast, the inhabitants of Pholus Delta Secundus, who have a major green sun and many minor blue suns (coincidentally with exactly the same orbital cycles), feel that green, blue and bleen are the natural categories...

 

Natural relative to the (current) universe

We've shown that some categories that we see as disjunctive or artificial can seem perfectly natural and fundamental to beings in different circumstances. Here's another example:

A philosopher proposes, as thought experiment, to define a certain concept for every object. It's the weighted sum of the inverse of the height of an object (from the centre of the Earth), and its speed (squared, because why not?), and its temperature (but only on an "absolute" scale), and some complicated thing involving its composition and shape, and another term involving its composition only. And maybe we can add another piece for its total mass.

And then that philosopher proposes, to great derision, that this whole messy sum be given a single name, "Energy", and that we start talking about it as if it was a single thing. Faced with such an artificially bizarre definition, sensible people who want to use induction properly have no choice... but to embrace energy as one of the fundamental useful facts of the universe.

What these example show is that green, blue, grue, bleen, and energy are not natural or non-natural categories in some abstract sense, but relative to the universe we inhabit. For instance, if we had some strange energy' which used the inverse of the height cubed, then we'd have a useless category - unless we lived in five spacial dimensions.

 

You're grue, what time is it?

So how can we say that green and blue are natural categories in our universe, while grue and bleen are not? A very valid explanation seems to be the dependence on X - on the time of day. In our earth, we can tell whether objects are green or blue without knowing anything about the time. Certainly we can get combined information about an object's colour and the time of day (for instance by looking at emeralds out in the open). But we also expect to get information about the colour (by looking at an object in a lit basement) and the time (by looking at a clock). And we expect these pieces of information to be independent of each other.

In contrast, we never expect to get information about an object being currently grue or currently bleen without knowing the time (or the colour, for that matter). And information about the time can completely change our assessment as to whether an object is grue versus bleen. It would be a very contrived set of circumstances where we would be able to assert "I'm pretty sure that object is currently grue, but I have no idea about its colour or about the current time".

Again, this is a feature of our world and the evidence we see in it, not some fundamental feature of the categories of grue and bleen. We just don't generally seen green objects change into blue objects, nor do we typically learn about disjunctive statements of the type "colour=green XOR time=night" without learning about the colour and the time separately.

What about the grue objects on Chiron Beta Prime? There, people do see objects change colour regularly, and, upon investigation, they can detect whether an object is grue without knowing either the time or the apparent colour of the object. For instance, they know that diamond is grue, so they can detect some grue objects by a simple hardness test.

But what's happening is that the Chiron Beta Primers have correctly identified a fundamental category - the one we call white, or, more technically "prone to reflect light both in the blue and green parts of the spectrum" - that has different features on their planet than on ours. From the macroscopic perspective, it's as if we and they live in a different universe, hence grue means something to them and not to us. But the same laws of physics underlie both our worlds, so fundamentally the concepts converge - our white, their grue, mean the same things at the microscopic level.

 

Definitions open to manipulation

In the next post, I'll look at whether we can formalise "expect independent information about colour and time", and "we don't expect change to the time information to change our colour assessment."

But be warned. The naturalness of these categories is dependent on facts about the universe, and these facts could be changed. A demented human (or a powerful AI) could go through the universe, hiding everything in boxes, smashing clocks, and putting "current bleen detectors" all other the place, so that it suddenly becomes very easy to know statements like "colour=blue XOR time=night", but very hard to know about colour (or time) independently from this. So it would be easy to say "this object is currently bleen", but hard to say "this object is blue". Thus the "natural" categories may be natural now, but this could well change, so we must have care when using these definitions to program an AI.

Top 9+2 myths about AI risk

43 Stuart_Armstrong 29 June 2015 08:41PM

Following some somewhat misleading articles quoting me, I thought Id present the top 10 myths about the AI risk thesis:

  1. That we’re certain AI will doom us. Certainly not. It’s very hard to be certain of anything involving a technology that doesn’t exist; we’re just claiming that the probability of AI going bad isn’t low enough that we can ignore it.
  2. That humanity will survive, because we’ve always survived before. Many groups of humans haven’t survived contact with more powerful intelligent agents. In the past, those agents were other humans; but they need not be. The universe does not owe us a destiny. In the future, something will survive; it need not be us.
  3. That uncertainty means that you’re safe. If you’re claiming that AI is impossible, or that it will take countless decades, or that it’ll be safe... you’re not being uncertain, you’re being extremely specific about the future. “No AI risk” is certain; “Possible AI risk” is where we stand.
  4. That Terminator robots will be involved. Please? The threat from AI comes from its potential intelligence, not from its ability to clank around slowly with an Austrian accent.
  5. That we’re assuming the AI is too dumb to know what we’re asking it. No. A powerful AI will know what we meant to program it to do. But why should it care? And if we could figure out how to program “care about what we meant to ask”, well, then we’d have safe AI.
  6. That there’s one simple trick that can solve the whole problem. Many people have proposed that one trick. Some of them could even help (see Holden’s tool AI idea). None of them reduce the risk enough to relax – and many of the tricks contradict each other (you can’t design an AI that’s both a tool and socialising with humans!).
  7. That we want to stop AI research. We don’t. Current AI research is very far from the risky areas and abilities. And it’s risk aware AI researchers that are most likely to figure out how to make safe AI.
  8. That AIs will be more intelligent than us, hence more moral. It’s pretty clear than in humans, high intelligence is no guarantee of morality. Are you really willing to bet the whole future of humanity on the idea that AIs might be different? That in the billions of possible minds out there, there is none that is both dangerous and very intelligent?
  9. That science fiction or spiritual ideas are useful ways of understanding AI risk. Science fiction and spirituality are full of human concepts, created by humans, for humans, to communicate human ideas. They need not apply to AI at all, as these could be minds far removed from human concepts, possibly without a body, possibly with no emotions or consciousness, possibly with many new emotions and a different type of consciousness, etc... Anthropomorphising the AIs could lead us completely astray.
Lists cannot be comprehensive, but they can adapt and grow, adding more important points:
  1. That AIs have to be evil to be dangerous. The majority of the risk comes from indifferent or partially nice AIs. Those that have some goal to follow, with humanity and its desires just getting in the way – using resources, trying to oppose it, or just not being perfectly efficient for its goal.
  2. That we believe AI is coming soon. It might; it might not. Even if AI is known to be in the distant future (which isn't known, currently), some of the groundwork is worth laying now.

 

​My recent thoughts on consciousness

-1 AlexLundborg 24 June 2015 12:37AM

I have lately come to seriously consider the view that the everyday notion of consciousness doesn’t refer to anything that exists out there in the world but is rather a confused (but useful) projection made by purely physical minds onto their depiction of themselves in the world. The main influences on my thinking are Dan Dennett, (I assume most of you are familiar with him)  and to a lesser extent Yudkowsky (1) and Tomasik (2). To use Dennett’s line of thought: we say that honey is sweet, that metal is solid or that a falling tree makes a sound, but the character tag of sweetness and sounds is not in the world but in the brains internal model of it. Sweetness in not an inherent property of the glucose molecule, instead, we are wired by evolution to perceive it as sweet to reward us for calorie intake in our ancestral environment, and there is neither any need for non-physical sweetness-juice in the brain – no, it's coded (3). We can talk about sweetness and sound as if being out there in the world but in reality it is a useful fiction of sorts that we are "projecting" out into the world. The default model of our surroundings and ourselves we use in our daily lives (the manifest image, or ’umwelt’) is puzzling to reconcile with the scientific perspective of gluons and quarks. We can use this insight to look critically on how we perceive a very familiar part of the world: ourselves. It might be that we are projecting useful fictions onto our model of ourselves as well. Our normal perception of consciousness is perhaps like the sweetness of honey, something we think exist in the world, when it is in fact a judgement about the world made (unconsciously) by the mind.

What we are pointing at with the judgement “I am conscious” is perhaps the competence that we have to access states about the world, form expectations about those states and judge their value to us, coded in by evolution. That is, under this view, equivalent with saying that suger is made of glucose molecules, not sweetness-magic. In everyday language we can talk about suger as sweet and consciousness as “something-to-be-like-ness“ or “having qualia”, which is useful and probably necessary for us to function, but that is a somewhat misleading projection made by our ​​world-accessing and assessing consciousness that really exists in the world. That notion of consciousness is not subject to the Hard Problem, it may not be an easy problem to figure out how consciousness works, but it does not appear impossible to explain it scientifically as pure matter like anything else in the natural world, at least in theory. I’m pretty confident that we will solve consciousness, if we by consciousness mean the competence of a biological system to access states about the world, make judgements and form expectations. That is however not what most people mean when they say consciousness. Just like ”real” magic refers to the magic that isn’t real and the magic that is real, that can be performed in the world, is not “real magic”, “real” consciousness turns out to be a useful, but misleading assessment (4). We should perhaps keep the word consciousness but adjust what we mean when we use it, for diplomacy.

Having said that, I still find myself baffled by the idea that I might not be conscious in the way I’ve found completely obvious before. Consciousness seems so mysterious and unanswerable, so it’s not surprising then that the explanation provided by physicalists like Dennett isn’t the most satisfying. Despite that, I think it’s the best explanation I've found so far, so I’m trying to cope with it the best I can. One of the problems I’ve had with the idea is how it has required me to rethink my views on ethics. I sympathize with moral realism, the view that there exist moral facts, by pointing to the strong intuition that suffering seems universally bad, and well-being seems universally good. Nobody wants to suffer agonizing pain, everyone wants beatific eudaimonia, and it doesn't feel like an arbitrary choice to care about the realization of these preferences in all sentience to a high degree, instead of any other possible goal like paperclip maximization. It appeared to me to be an unescapable fact about the universe that agonizing pain really is bad (ought to be prevented), that intelligent bliss really is good (ought to be pursued), like a label to distinguish wavelength of light in the brain really is red, and that you can build up moral values from there. I have a strong gut feeling that the well-being of sentience matters, and the more capacity a creature has of receiving pain and pleasure the more weight it is given, say a gradience from beetles to posthumans that could perhaps be understood by further inquiry of the brain (5). However, if it turns out that pain and pleasure isn’t more than convincing judgements by a biological computer network in my head, no different in kind to any other computation or judgement, the sense of seriousness and urgency of suffering appears to fade away. Recently, I’ve loosened up a bit to accept a weaker grounding for morality: I still think that my own well-being matter, and I would be inconsistent if I didn’t think the same about other collections of atoms that appears functionally similar to ’me’, who also claim, or appear, to care about their well-being. I can’t answer why I should care about my own well-being though, I just have to. Speaking of 'me': personal identity also looks very different (nonexistent?) under physicalism, than in the everyday manifest image (6).

Another difficulty I confront is why e.g. colors and sounds looks and sounds the way they do or why they have any quality at all, under this explanation. Where do they come from if they’re only labels my brain uses to distinguish inputs from the senses? Where does the yellowness of yellow come? Maybe it’s not a sensible question, but only the murmuring of a confused primate. Then again, where does anything come from? If we can learn to shut up our bafflement about consciousness and sensibly reduce it down to physics – fair enough, but where does physics come from? That mystery remains, and that will possibly always be out of reach, at least probably before advanced superintelligent philosophers. For now, understanding how a physical computational system represents the world, creates judgements and expectations from perception presents enough of a challenge. It seems to be a good starting point to explore anyway (7).


I did not really put forth any particularly new ideas here, this is just some of my thoughts and repetitions of what I have read and heard others say, so I'm not sure if this post adds any value. My hope is that someone will at least find some of my references useful, and that it can provide a starting point for discussion. Take into account that this is my first post here, I am very grateful to receive input and criticism! :-)

  1. Check out Eliezer's hilarious tear down of philosophical zombies if you haven't already
  2. http://reducing-suffering.org/hard-problem-consciousness/
  3. [Video] TED talk by Dan Dennett http://www.ted.com/talks/dan_dennett_cute_sexy_sweet_funny
  4. http://ase.tufts.edu/cogstud/dennett/papers/explainingmagic.pdf
  5. Reading “The Moral Landscape” by Sam Harris increased my confidence in moral realism. Whether moral realism is true of false can obviously have implications for approaches to the value learning problem in AI alignment, and for the factual accuracy of the orthogonality thesis
  6. http://www.lehigh.edu/~mhb0/Dennett-WhereAmI.pdf
  7. For anyone interested in getting a grasp of this scientific challenge I strongly recommend the book “A User’s Guide to Thought and Meaning” by Ray Jackendoff.



Edit: made some minor changes and corrections. Edit 2: made additional changes in the first paragraph for increased readability.

 


[Link] Self-Representation in Girard’s System U

2 Gunnar_Zarncke 18 June 2015 11:22PM

Self-Representation in Girard’s System U, by Matt Brown and Jens Palsberg:

In 1991, Pfenning and Lee studied whether System F could support a typed self-interpreter. They concluded that typed self-representation for System F “seems to be impossible”, but were able to represent System F in Fω. Further, they found that the representation of Fω requires kind polymorphism, which is outside Fω. In 2009, Rendel, Ostermann and Hofer conjectured that the representation of kind-polymorphic terms would require another, higher form of polymorphism. Is this a case of infinite regress?
We show that it is not and present a typed self-representation for Girard’s System U, the first for a λ-calculus with decidable type checking. System U extends System Fω with kind polymorphic terms and types. We show that kind polymorphic types (i.e. types that depend on kinds) are sufficient to “tie the knot” – they enable representations of kind polymorphic terms without introducing another form of polymorphism. Our self-representation supports operations that iterate over a term, each of which can be applied to a representation of itself. We present three typed self-applicable operations: a self-interpreter that recovers a term from its representation, a predicate that tests the intensional structure of a term, and a typed continuation-passing-style (CPS) transformation – the first typed self-applicable CPS transformation. Our techniques could have applications from verifiably type-preserving metaprograms, to growable typed languages, to more efficient self-interpreters.
Emphasis mine. That seems to be a powerful calculus for writing self-optimizing AI programs in...

See also the lambda-the-ultimate comment thread about it.

The president didn't die: failures at extending AI behaviour

9 Stuart_Armstrong 10 June 2015 04:00PM

A putative new idea for AI control; index here.

In a previous post, I considered the issue of an AI that behaved "nicely" given some set of circumstances, and whether we could extend that behaviour to the general situation, without knowing what "nice" really meant.

The original inspiration for this idea came from the idea of extending the nice behaviour of "reduced impact AI" to situations where they didn't necessarily have a reduced impact. But it turned out to be connected with "spirit of the law" ideas, and to be of potentially general interest.

Essentially, the problem is this: if we have an AI that will behave "nicely" (since this could be a reduced impact AI, I don't use the term "friendly", which denotes a more proactive agent) given X, how can we extend its "niceness" to ¬X? Obviously if we can specify what "niceness" is, we could just require the AI to do so given ¬X. Therefore let us assume that we don't have a good definition of "niceness", we just know that the AI has that given X.

To make the problem clearer, I chose an X that would be undeniably public and have a large (but not overwhelming) impact: the death of the US president on a 1st of April. The public nature of this event prevents using approaches like thermodynamic miracles to define counterfactuals.

I'll be presenting a solution in a subsequent post. In the meantime, to help better understand the issue, here's a list of failed solutions:

 

First Failure: maybe there's no problem

Initially, it wasn't clear there was a problem. Could we just expect niceness to extend naturally? But consider the following situation: assume the vice president is a warmonger, who will start a nuclear war if ever they get into power (but is otherwise harmless).

Now assume the nice AI has the conditional action criteria: "if the vice president ever becomes president, launch a coup". This is safe, it can be extended to the ¬X situation in the way we want.

However, conditioning on X, that criteria is equivalent with "launch a coup on the 2nd of April". And if the AI has that criteria, then extending it to ¬X is highly non-safe. This illustrates that there is a real problem here - the coup example is just one of the myriad of potential issues that could arise, and we can't predict them all.

 

Second failure: don't condition on X

Maybe the trick could be preventing the AI from conditioning on X (for anything)? If the AI itself can't tell the difference between X and ¬X, wouldn't its nice behaviour extend?

But this doesn't help. The AI could merely condition on things tightly coupled with X. Like news reports of the president's demise, or a conjunction of other events almost impossible under ¬X.

 

Third failure: disbelieve the truth

In this design, the AI simply assumes that X happens, whatever the evidence. Therefore it would stay nice, whatever happened.

But this results in an AI who's beliefs are strongly decoupled with reality. The AI must believe that there is a vast conspiracy concealing the president's death; the more it investigates this conspiracy, and fails to find it, the more vast and powerful it becomes. What if you show it undeniable, impossible-to-fake-by-the-laws-of-physics evidence of the president's demise? Then it starts to believe that the laws of physics are all wrong.

Though the AI is "nice", it's niceness is appropriate for a world of invisible conspiracies and alternate physics - not for the real world. It's clear how such an AI could start doing crazy and dangerous things as its view of reality starts to diverge.

 

Fourth failure: hack the models

This example is due to Daniel Dewey. He imagined that the AI would maintain a full collection of models and update them normally. But before making a prediction, each model would get hacked to artificially set ¬X to X.

To see how this could fail, imagine all evidence about the world is stored in a giant vector of data. These vectors are calibrated correctly, then ¬X is flipped to X. The problem is that, while that is small change to the vector, it could be a huge change to the world that it encodes.

For instance, let's go back to the warmongering vice president, and assume that nuclear war is inevitable, given X. Then the AI will walk around in a peaceful world, update its models - and act as if it was in a nuclear wasteland, because those are the only possibilities, given X. Essentially, the AI will move through our universe, harvesting information that would inform its actions in a parallel universe - and acting as if it existed there instead of here.

For instance, it could wander into a flower show where someone is talking about difficulties growing roses in southern Quebec. It adds this data to its vector, noting that the soil there must be a bit unsuitable to plant growth. It therefore concludes that it must write to the (non-existent) Third God-Emperor of America and advise it to give up on the Quebec Anglican Protectorate, which must be misreporting their agriculture output, given this data.

It's interesting to contrast this AI with the previous one. Suppose that the nuclear war further implies that Paris must be a smoking crater. And now both AIs must walk around a clearly bustling and intact Paris. The disbelieving AI must conclude that this is an elaborate ruse - someone has hidden the crater from its senses, put up some fake building, etc... The model-hacking AI, meanwhile, acts as if it's in a smouldering crater, with the genuine Paris giving it information as to what it should do: it sees an intact army barracks, and starts digging under the "rubble" to see if anything "remains" of that barracks.

It would be interesting to get Robin Hanson to try and reconcile these AIs' beliefs ^_^

 

Fifth failure: Bayes nets and decisions

It seems that a Bayes net would be our salvation. We could have dependent nodes like "warmongering president", "nuclear war", or "flower show". Then we could require that the AI makes its decision dependent only on the states of these dependent nodes. And never on the original X/¬X node.

This seems safe - after all, the AI is nice given X. And if we require the AI's decisions be dependent only on subordinate nodes, then it must be nice dependent on the subordinate nodes. Therefore X/¬X is irrelevant, and the AI is always nice.

Except... Consider what a "decision" is. A decision could be something simple, or it could be "construct a sub AI that will establish X versus ¬X, and do 'blah' if X, and 'shmer' if ¬X". That's a perfectly acceptable decision, and could be made conditional on any (or all) of the subordinate nodes. And if 'blah' is nice while 'shmer' isn't, we have the same problem.

 

Six failure: Bayes nets and unnatural categories

OK, if decisions are too general, how about values for worlds? We take a lot of nodes, subordinate to X/¬X, and require that the AI define its utility or value function purely in terms of the states of these subordinate nodes. Again, this seems safe. The AI's value function is safe given X, by assumption, and is defined in terms of subordinate nodes that "screen off" X/¬X.

And that AI is indeed safe... if the subordinate nodes are sensible. But they're only sensible because I've defined them using terms such as "nuclear war". But what if a node is "nuclear war if X and peace in our time if ¬X"? That's a perfectly fine definition. But such nodes mean that the value function given ¬X need not be safe in any way.

This is somewhat connected with the Grue and Bleen issue, and addressing that is how I'll be hoping to solve the general problem.

Help needed: nice AIs and presidential deaths

1 Stuart_Armstrong 08 June 2015 04:47PM

A putative new idea for AI control; index here.

This is a problem that developed from the "high impact from low impact" idea, but is a legitimate thought experiment in its own right (it also has connections with the "spirit of the law" idea).

Suppose that, next 1st of April, the US president may or may not die of natural causes. I chose this example because it's an event of potentially large magnitude, but not overwhelmingly so (neither a butterfly wing nor an asteroid impact).

Also assume that, for some reason, we are able to program an AI that will be nice, given that the president does die on that day. Its behaviour if the president doesn't die is undefined and potentially dangerous.

Is there a way (either at the initial stages of programming or at the later) to extend the "niceness" from the "presidential death world" into the "presidential survival world"?

To focus on how tricky the problem is, assume for argument's sake that the vice-president is a war monger that will start a nuclear war if they become president. Then "launch a coup on the 2nd of April" is a "nice" thing of the AI to do, conditional on the president dying. However, if you naively import that requirement into the "presidential survival world", the AI will launch a pointeless and counterproductive coup. This is illustrative of the kind of problems that could come up.

So the question is, can we transfer niceness in this way, without needing a solution to the full problem of niceness in general?

EDIT: Actually, this seems ideally setup for a Bayes network (or for the requirement that a Bayes network be used).

EDIT2: Now the problem of predicates like "Grue" and "Bleen" seem to be the relevant bit. If you can avoid concepts such as "X={nuclear war if president died, peace if president lived}", you can make the extension work.

An Oracle standard trick

4 Stuart_Armstrong 03 June 2015 02:17PM

A putative new idea for AI control; index here.

EDIT: To remind everyone, this method does not entail the Oracle having false beliefs, just behaving as if it did; see here and here.

An idea I thought I'd been mentioning to everyone, but a recent conversation reveals I haven't been assiduous about it.

It's quite simple: whenever designing an Oracle, you should, as a default, run it's output channel through a probabilistic process akin to the false thermodynamic miracle, in order to make the Oracle act as if it believed its message will never be read.

This reduces the possibility of the Oracle manipulating us through message content, because it's action as if that content will never be seen by anyone.

Now, some Oracle designs can't use that (eg if accuracy is defined in terms of the reaction of people that read its output). But in general, if your design allows such a precaution, there's no reason not to put it on, so it should be default in the Oracle design.

Even if the Oracle design precludes this directly, some version of it can be often be used. For instance, if accuracy is defined in terms of the reaction of the first person to read the output, and that person is isolated from the rest of the world, then we can get the Oracle to act as if it believed a nuclear bomb was due to go off before the person could communicate with the rest of the world.

How do humans assign utilities to world states?

2 Dorikka 31 May 2015 08:40PM

It seems like a good portion of the whole "maximizing utility" strategy which might be used by a sovereign relies on actually being able to consolidate human preferences into utilities. I think there are a few stages here, each of which may present obstacles. I'm not sure what the current state of the art is with regard to overcoming these, and am curious regarding such.

First, here are a few assumptions that I'm using just to make the problem a bit more navigable (dealing with one or two hard problems instead of a bunch at once) - will need to go back and do away with each of these (and each combination thereof) and see what additional problems result.

  1. The sovereign has infinite computing power (and to shorten the list of assumptions, can do 2-6 below)
  2. We're maximizing across the preferences of a single human (Alice for convenience). To the extent that Alice cares about others, we're accounting for their preferences, too. But we're not dealing with aggregating preferences across different sentient beings, yet. I think this is a separate hard problem.
  3. Alice has infinite computing power.
  4. We're assuming that Alice's preferences do not change and cannot change, ever, no matter what happens. So as Alice experiences different things in her life, she has the exact same preferences. No matter what she learns or concludes about the world, she has the exact same preferences. To be explicit, this includes preferences regarding the relative weightings of present and future worldstates. (And in CEV terms, no spread, no distance.)
  5. We're assuming that Alice (and the sovereign) can deductively conclude the future from the present, given a particular course of action by the sovereign. Picture a single history of the universe from the beginning of the universe to now, and a bunch of worldlines running into the future depending on what action the sovereign takes. To clarify, if you ask Alice about any single little detail across any of the future worldlines, she can tell you that detail.
  6. Alice can read minds and the preferences of other humans and sentient beings (implied by 5, but trying to be explicit.)

So Alice can conclude anything and everything, pretty much (and so can our sovereign.) The sovereign is faced with the problem of figuring out what action to take to maximize across Alice's preferences. However, Alice is basically a sack of meat that has certain emotions in response to certain experiences or certain conclusions about the world, and it doesn't seem obvious how to get the preference ordering of the different worldlines out of these emotions. Some difficulties:

  1. The sovereign notices that Alice experiences different feelings in response to different stimuli. How does the sovereign determine which types of feelings to maximize, and which to minimize? There are a bunch of ways to deal with this, but most of them seem to have a chance of error (and the conjunction of p(error) across all the times that the sovereign will need to do this approach 1). For example, could train off an existing data set, could have it simulate other humans with access to Alice's feelings and cognition and have a simulated committee discuss and reach a decision on each one, etc etc. But all of these bootstrap off of the assumed ability of humans to determine which feelings to maximize (just with amped up computing power) - this doesn't strike me as a satisfactory solution.
  2. Assume 1. is solved. The sovereign knows which feelings to maximize. However, it's ended up with a bunch of axes. How does it determine the appropriate trade-offs to make? (Or, to put it another way, how does it determine the relative value of different positions along each axis with different positions along different axes?)

So, to rehash my actual request: what's the state of the art with regards to these difficulties, and how confident are we that we've reached a satisfactory answer?

Learning to get things right first time

8 owencb 29 May 2015 10:06PM

These are quick notes on an idea for an indirect strategy to increase the likelihood of society acquiring robustly safe and beneficial AI.

 

Motivation:

  • Most challenges we can approach with trial-and-error, so many of our habits and social structures are set up to encourage this. There are some challenges where we may not get this opportunity, and it could be very helpful to know what methods help you to tackle a complex challenge that you need to get right first time.

  • Giving an artificial intelligence good values may be a particularly important challenge, and one where we need to be correct first time. (Distinct from creating systems that act intelligently at all, which can be done by trial and error.)

  • Building stronger societal knowledge about how to approach such problems may make us more robustly prepared for such challenges. Having more programmers in the AI field familiar with the techniques is likely to be particularly important.

 

Idea: Develop methods for training people to write code without bugs.

  • Trying to teach the skill of getting things right first time.

  • Writing or editing code that has to be bug-free without any testing is a fairly easy challenge to set up, and has several of the right kind of properties. There are some parallels between value specification and programming.

  • Set-up puts people in scenarios where they only get one chance -- no opportunity to test part/all of the code, just analyse closely before submitting.

    • Interested in personal habits as well as social norms or procedures that help this.

      • Daniel Dewey points to standards for code on the space shuttle as a good example of getting high reliability code edits.

 

How to implement:

  • Ideal: Offer this training to staff at software companies, for profit.

    • Although it’s teaching a skill under artificial hardship, it seems plausible that it could teach enough good habits and lines of thinking to noticeably increase productivity, so people would be willing to pay for this.

    • Because such training could create social value in the short run, this might give a good opportunity to launch as a business that is simultaneously doing valuable direct work.

    • Similarly, there might be a market for a consultancy that helped organisations to get general tasks right the first time, if we knew how to teach that skill.

  • More funding-intensive, less labour intensive: run competitions with cash prizes

    • Try to establish it as something like a competitive sport for teams.

    • Outsource the work of determining good methods to the contestants.

 

This is all quite preliminary and I’d love to get more thoughts on it. I offer up this idea because I think it would be valuable but not my comparative advantage. If anyone is interested in a project in this direction, I’m very happy to talk about it.

Concept Safety: World-models as tools

6 Kaj_Sotala 09 May 2015 12:07PM

 I'm currently reading through some relevant literature for preparing my FLI grant proposal on the topic of concept learning and AI safety. I figured that I might as well write down the research ideas I get while doing so, so as to get some feedback and clarify my thoughts. I will posting these in a series of "Concept Safety"-titled articles.

The AI in the quantum box

In the previous post, I discussed the example of an AI whose concept space and goals were defined in terms of classical physics, which then learned about quantum mechanics. Let's elaborate on that scenario a little more.

I wish to zoom in on a certain assumption that I've noticed in previous discussions of these kinds of examples. Although I couldn't track down an exact citation right now, I'm pretty confident that I've heard the QM scenario framed as something like "the AI previously thought in terms of classical mechanics, but then it finds out that the world actually runs on quantum mechanics". The key assumption being that quantum mechanics is in some sense more real than classical mechanics.

This kind of an assumption is a natural one to make if someone is operating on an AIXI-inspired model of AI. Although AIXI considers an infinite amount of world-models, there's a sense in which AIXI always strives to only have one world-model. It's always looking for the simplest possible Turing machine that would produce all of the observations that it has seen so far, while ignoring the computational cost of actually running that machine. AIXI, upon finding out about quantum mechanics, would attempt to update its world-model into one that only contained QM primitives and to derive all macro-scale events right from first principles.

No sane design for a real-world AI would try to do this. Instead, a real-world AI would take advantage of scale separation. This refers to the fact that physical systems can be modeled on a variety of different scales, and it is in many cases sufficient to model them in terms of concepts that are defined in terms of higher-scale phenomena. In practice, the AI would have a number of different world-models, each of them being applied in different situations and for different purposes.

Here we get back to the view of concepts as tools, which I discussed in the previous post. An AI that was doing something akin to reinforcement learning would come to learn the kinds of world-models that gave it the highest rewards, and to selectively employ different world-models based on what was the best thing to do in each situation.

As a toy example, consider an AI that can choose to run a low-resolution or a high-resolution psychological model of someone it's interacting with, in order to predict their responses and please them. Say the low-resolution model takes a second to run and is 80% accurate; the high-resolution model takes five seconds to run and is 95% accurate. Which model will be chosen as the one to be used will depend on the cost matrix of making a correct prediction, making a false prediction, and the consequence of making the other person wait for an extra four seconds before the AI's each reply.

We can now see that a world-model being the most real, i.e. making the most accurate predictions, doesn't automatically mean that it will be used. It also needs to be fast enough to run, and the predictions need to be useful for achieving something that the AI cares about.

World-models as tools

From this point of view, world-models are literally tools just like any other. Traditionally in reinforcement learning, we would define the value of a policy  in state s as the expected reward given the state s and the policy ,

but under the "world-models are tools" perspective, we need to also condition on the world-model m,

 .

We are conditioning on the world-model in several distinct ways.

First, there is the expected behavior of the world as predicted by world-model m. A world-model over the laws of social interaction would do poorly at predicting the movement of celestial objects, if it could be applied to them at all. Different predictions of behavior may also lead to differing predictions of the value of a state. This is described by the equation above.

Second, there is the expected cost of using the world-model. Using a more detailed world-model may be more computationally expensive, for instance. One way of interpreting this in a classical RL framework would be that using a specific world-model will place the agent in a different state than using some other world-model. We might describe by saying that in addition to the agent choosing its next action a on each time-step, the agent also needs to choose the world-model m which it will use to analyze its next observations. This will be one of the inputs for the transition function  to the next state.

Third, there is the expected behavior of the agent using world-model m. An agent with different beliefs about the world will act differently in the future: this means that the future policy  actually depends on the chosen world-model.

Some very interesting questions pop up at this point. Your currently selected world-model is what you use to evaluate your best choices for the next step... including the choice of what world-model to use next. So whether or not you're going to switch to a different world-model for evaluating the next step depends on whether your current world-model says that a different world-model would be better in that step.

We have not fully defined what exactly we mean by "world-models" here. Previously I gave the example of a world-model over the laws of social interaction, versus a world-model over the laws of physics. But a world-model over the laws of social interaction, say, would not have an answer to the question of which world-model to use for things it couldn't predict. So one approach would be to say that we actually have some meta-model over world-models, telling us which is the best to use in what situation.

On the other hand, it does also seem like humans often use a specific world-model and its predictions to determine whether to choose another world-model. For example, in rationalist circles you often see arguments to the line of, "self-deception might give you extra confidence, but it introduces errors into your world-model, and in the long term those are going to be more harmful than the extra confidence is beneficial". Here you see an implicit appeal to a world-model which predicts an accumulation of false beliefs with some specific effects, as well as predicting the extra self-esteem with its effects. But this kind of an analysis incorporates very specific causal claims from various (e.g. psychological) models, which are models over the world rather than just being part of some general meta-model over models. Notice also that the example analysis takes into account the way that having a specific world-model affects the state transition function: it assumes that a self-deceptive model may land us in a state where we have a higher self-esteem.

It's possible to get stuck in one world-model: for example, a strongly non-reductionist model evaluating the claims of a highly reductionist one might think it obviously crazy, and vice versa. So it seems that we do need something like a meta-evaluation function. Otherwise it would be too easy to get stuck in one model which claimed that it was the best one in every possible situation, and never agreed to "give up control" in favor of another one.

One possibility for such a thing would be a relatively model-free learning mechanism, which just kept track of the rewards accumulated when using a particular model in a particular situation. It would then bias the selection of the model towards the direction of the model that had been the most successful so far.

Human neuroscience and meta-models

We might be able to identify something like this in humans, though this is currently very speculative on my part. Action selection is carried out in the basal ganglia: different brain systems send the basal ganglia "bids" for various actions. The basal ganglia then chooses which actions to inhibit or disinhibit (by default, everything is inhibited). The basal ganglia also implements reinforcement learning, selectively strengthening or weakening the connections associated with a particular bid and context when a chosen action leads to a higher or lower reward than was expected. It seems that in addition to choosing between motor actions, the basal ganglia also chooses between different cognitive behaviors, likely even thoughts

If action selection and reinforcement learning are normal functions of the basal ganglia, it should be possible to interpret many of the human basal ganglia-related disorders in terms of selection malfunctions. For example, the akinesia of Parkinson's disease may be seen as a failure to inhibit tonic inhibitory output signals on any of the sensorimotor channels. Aspects of schizophrenia, attention deficit disorder and Tourette's syndrome could reflect different forms of failure to maintain sufficient inhibitory output activity in non-selected channels. Conseqently, insufficiently inhibited signals in non-selected target structures could interfere with the output of selected targets (expressed as motor/verbal tics) and/or make the selection system vulnerable to interruption from distracting stimuli (schizophrenia, attention deficit disorder). The opposite situation would be where the selection of one functional channel is abnormally dominant thereby making it difficult for competing events to interrupt or cause a behavioural or attentional switch. Such circumstances could underlie addictive compulsions or obsessive compulsive disorder. (Redgrave 2007)

Although I haven't seen a paper presenting evidence for this particular claim, it seems plausible to assume that humans similarly come to employ new kinds of world-models based on the extent to which using a particular world-model in a particular situation gives them rewards. When a person is in a situation where they might think in terms of several different world-models, there will be neural bids associated with mental activities that recruit the different models. Over time, the bids associated with the most successful models will become increasingly favored. This is also compatible with what we know about e.g. happy death spirals and motivated stopping: people will tend to have the kinds of thoughts which are rewarding to them.

The physicist and the AI

In my previous post, when discussing the example of the physicist who doesn't jump out of the window when they learn about QM and find out that "location" is ill-defined:

The physicist cares about QM concepts to the extent that the said concepts are linked to things that the physicist values. Maybe the physicist finds it rewarding to develop a better understanding of QM, to gain social status by making important discoveries, and to pay their rent by understanding the concepts well enough to continue to do research. These are some of the things that the QM concepts are useful for. Likely the brain has some kind of causal model indicating that the QM concepts are relevant tools for achieving those particular rewards. At the same time, the physicist also has various other things they care about, like being healthy and hanging out with their friends. These are values that can be better furthered by modeling the world in terms of classical physics. [...]

A part of this comes from the fact that the physicist's reward function remains defined over immediate sensory experiences, as well as values which are linked to those. Even if you convince yourself that the location of food is ill-defined and you thus don't need to eat, you will still suffer the negative reward of being hungry. The physicist knows that no matter how they change their definition of the world, that won't affect their actual sensory experience and the rewards they get from that.

So to prevent the AI from leaving the box by suitably redefining reality, we have to somehow find a way for the same reasoning to apply to it. I haven't worked out a rigorous definition for this, but it needs to somehow learn to care about being in the box in classical terms, and realize that no redefinition of "location" or "space" is going to alter what happens in the classical model. Also, its rewards need to be defined over models to a sufficient extent to avoid wireheading (Hibbard 2011), so that it will think that trying to leave the box by redefining things would count as self-delusion, and not accomplish the things it really cared about. This way, the AI's concept for "being in the box" should remain firmly linked to the classical interpretation of physics, not the QM interpretation of physics, because it's acting in terms of the classical model that has always given it the most reward. 

There are several parts to this.

1. The "physicist's reward function remains defined over immediate sensory experiences". Them falling down and breaking their leg is still going to hurt, and they know that this won't be changed no matter how they try to redefine reality.

2. The physicist's value function also remains defined over immediate sensory experiences. They know that jumping out of a window and ending up with all the bones in their body being broken is going to be really inconvenient even if you disregarded the physical pain. They still cannot do the things they would like to do, and they have learned that being in such a state is non-desirable. Again, this won't be affected by how they try to define reality.

We now have a somewhat better understanding of what exactly this means. The physicist has spent their entire life living in the classical world, and obtained nearly all of their rewards by thinking in terms of the classical world. As a result, using the classical model for reasoning about life has become strongly selected for. Also, the physicist's classical world-model predicts that thinking in terms of that model is a very good thing for surviving, and that trying to switch to a QM model where location was ill-defined would be a very bad thing for the goal of surviving. On the other hand, thinking in terms of exotic world-models remains a rewarding thing for goals such as obtaining social status or making interesting discoveries, so the QM model does get more strongly reinforced in that context and for that purpose.

Getting back to the question of how to make the AI stay in the box, ideally we could mimic this process, so that the AI would initially come to care about staying in the box. Then when it learns about QM, it understands that thinking in QM terms is useful for some goals, but if it were to make itself think in purely QM terms, that would cause it to leave the box. Because it is thinking mostly in terms of a classical model, which says that leaving the box would be bad (analogous to the physicist thinking mostly in terms of the classical model which says that jumping out of the window would be bad), it wants to make sure that it will continue to think in terms of the classical model when it's reasoning about its location.

CFAR-run MIRI Summer Fellows program: July 7-26

22 AnnaSalamon 28 April 2015 07:04PM

CFAR will be running a three week summer program this July for MIRI, designed to increase participants' ability to do technical research into the superintelligence alignment problem.

The intent of the program is to boost participants as far as possible in four skills:

  1. The CFAR “applied rationality” skillset, including both what is taught at our intro workshops, and more advanced material from our alumni workshops;
  2. “Epistemic rationality as applied to the foundations of AI, and other philosophically tricky problems” -- i.e., the skillset taught in the core LW Sequences.  (E.g.: reductionism; how to reason in contexts as confusing as anthropics without getting lost in words.)
  3. The long-term impacts of AI, and strategies for intervening (e.g., the content discussed in Nick Bostrom’s book Superintelligence).
  4. The basics of AI safety-relevant technical research.  (Decision theory, anthropics, and similar; with folks trying their hand at doing actual research, and reflecting also on the cognitive habits involved.)

The program will be offered free to invited participants, and partial or full scholarships for travel expenses will be offered to those with exceptional financial need.

If you're interested (or possibly-interested), sign up for an admissions interview ASAP at this link (takes 2 minutes): http://rationality.org/miri-summer-fellows-2015/

Also, please forward this post, or the page itself, to anyone you think should come; the skills and talent that humanity brings to bear on the superintelligence alignment problem may determine our skill at navigating it, and sharing this opportunity with good potential contributors may be a high-leverage way to increase that talent.

High impact from low impact, continued

2 Stuart_Armstrong 28 April 2015 12:58PM

A putative new idea for AI control; index here.

The idea of splitting a high impact task between two low-impact AIs has on critical flaw. AI X is aiming for low impact, conditional on ¬Y (the other AI not being turned on, or not outputting a message, or something similar). "Outputting the right coordinates" is one way that X can accomplish its goal. However, there is another way it can do it: "create a robot that will output the right coordinates if ¬Y, and [do something else] if Y."

That's a dangerous situation to be in, especially if we have a more general situation that the "laser aiming at the asteroid". But note that if X does create such a robot, and if ¬Y is actually true, then that robot must be low impact and not dangerous, since that's X's programming. Since X cannot predict all the situations the robot would encounter, the robot is probably generically "safe" and low impact.

Therefore, if the robot behaves the same way under Y and ¬Y, we're good.

How could we achieve that? Well, we could adapt my idea from "restrictions that are hard to hack". If a hypothetical superintelligent AI C observed the output stream from X, could it deduce that Y vs ¬Y was something important in it? If C knew that X was conditioning on ¬Z, but didn't know Z=Y, could it deduce that? That seems like a restriction that we could program into X, as a third component of its utility (the first being the "do what we want" component, the second being the "have a reduced impact conditional on ¬Z" one).

And if we have a "safe" robot, given ¬Y, and the programming of that robot does not (explicitly or implicitly) mention Y or its features, we probably have a safe robot.

The idea still needs to be developed and some of the holes patched, but I feel it has potential.

Concept Safety: What are concepts for, and how to deal with alien concepts

11 Kaj_Sotala 19 April 2015 01:44PM

I'm currently reading through some relevant literature for preparing my FLI grant proposal on the topic of concept learning and AI safety. I figured that I might as well write down the research ideas I get while doing so, so as to get some feedback and clarify my thoughts. I will posting these in a series of "Concept Safety"-titled articles.

In The Problem of Alien Concepts, I posed the following question: if your concepts (defined as either multimodal representations or as areas in a psychological space) previously had N dimensions and then they suddenly have N+1, how does that affect (moral) values that were previously only defined in terms of N dimensions?

I gave some (more or less) concrete examples of this kind of a "conceptual expansion":

  1. Children learn to represent dimensions such as "height" and "volume", as well as "big" and "bright", separately at around age 5.
  2. As an inhabitant of the Earth, you've been used to people being unable to fly and landowners being able to forbid others from using their land. Then someone goes and invents an airplane, leaving open the question of the height to which the landowner's control extends. Similarly for satellites and nation-states.
  3. As an inhabitant of Flatland, you've been told that the inside of a certain rectangle is a forbidden territory. Then you learn that the world is actually three-dimensional, leaving open the question of the height of which the forbidden territory extends.
  4. An AI has previously been reasoning in terms of classical physics and been told that it can't leave a box, which it previously defined in terms of classical physics. Then it learns about quantum physics, which allow for definitions of "location" which are substantially different from the classical ones.

As a hint of the direction where I'll be going, let's first take a look at how humans solve these kinds of dilemmas, and consider examples #1 and #2.

The first example - children realizing that items have a volume that's separate from their height - rarely causes any particular crises. Few children have values that would be seriously undermined or otherwise affected by this discovery. We might say that it's a non-issue because none of the children's values have been defined in terms of the affected conceptual domain.

As for the second example, I don't know the exact cognitive process by which it was decided that you didn't need the landowner's permission to fly over their land. But I'm guessing that it involved reasoning like: if the plane flies at a sufficient height, then that doesn't harm the landowner in any way. Flying would become impossible difficult if you had to get separate permission from every person whose land you were going to fly over. And, especially before the invention of radar, a ban on unauthorized flyovers would be next to impossible to enforce anyway.

We might say that after an option became available which forced us to include a new dimension in our existing concept of landownership, we solved the issue by considering it in terms of our existing values.

Concepts, values, and reinforcement learning

Before we go on, we need to talk a bit about why we have concepts and values in the first place.

From an evolutionary perspective, creatures that are better capable of harvesting resources (such as food and mates) and avoiding dangers (such as other creatures who think you're food or after their mates) tend to survive and have offspring at better rates than otherwise comparable creatures who are worse at those things. If a creature is to be flexible and capable of responding to novel situations, it can't just have a pre-programmed set of responses to different things. Instead, it needs to be able to learn how to harvest resources and avoid danger even when things are different from before.

How did evolution achieve that? Essentially, by creating a brain architecture that can, as a very very rough approximation, be seen as consisting of two different parts. One part, which a machine learning researcher might call the reward function, has the task of figuring out when various criteria - such as being hungry or getting food - are met, and issuing the rest of the system either a positive or negative reward based on those conditions. The other part, the learner, then "only" needs to find out how to best optimize for the maximum reward. (And then there is the third part, which includes any region of the brain that's neither of the above, but we don't care about those regions now.)

The mathematical theory of how to learn to optimize for rewards when your environment and reward function are unknown is reinforcement learning (RL), which recent neuroscience indicates is implemented by the brain. An RL agent learns a mapping from states of the world to rewards, as well as a mapping from actions to world-states, and then uses that information to maximize the amount of lifetime rewards it will get.

There are two major reasons why an RL agent, like a human, should learn high-level concepts:

  1. They make learning massively easier. Instead of having to separately learn that "in the world-state where I'm sitting naked in my cave and have berries in my hand, putting them in my mouth enables me to eat them" and that "in the world-state where I'm standing fully-clothed in the rain outside and have fish in my hand, putting it in my mouth enables me to eat it" and so on, the agent can learn to identify the world-states that correspond to the abstract concept of having food available, and then learn the appropriate action to take in all those states.
  2. There are useful behaviors that need to be bootstrapped from lower-level concepts to higher-level ones in order to be learned. For example, newborns have an innate preference for looking at roughly face-shaped things (Farroni et al. 2005), which develops into a more consistent preference for looking at faces over the first year of life (Frank, Vul & Johnson 2009). One hypothesis is that this bias towards paying attention to the relatively-easy-to-encode-in-genes concept of "face-like things" helps direct attention towards learning valuable but much more complicated concepts, such as ones involved in a basic theory of mind (Gopnik, Slaughter & Meltzoff 1994) and the social skills involved with it.

Viewed in this light, concepts are cognitive tools that are used for getting rewards. At the most primitive level, we should expect a creature to develop concepts that abstract over situations that are similar with regards to the kind of reward that one can gain from taking a certain action in those states. Suppose that a certain action in state s1 gives you a reward, and that there are also states s2 - s5 in which taking some specific action causes you to end up in s1. Then we should expect the creature to develop a common concept for being in the states s2 - s5, and we should expect that concept to be "more similar" to the concept of being in state s1 than to the concept of being in some state that was many actions away.

"More similar" how?

In reinforcement learning theory, reward and value are two different concepts. The reward of a state is the actual reward that the reward function gives you when you're in that state or perform some action in that state. Meanwhile, the value of the state is the maximum total reward that you can expect to get from moving that state to others (times some discount factor). So a state A with reward 0 might have value 5 if you could move from it to state B, which had a reward of 5.

Below is a figure from DeepMind's recent Nature paper, which presented a deep reinforcement learner that was capable of achieving human-level performance or above on 29 of 49 Atari 2600 games (Mnih et al. 2015). The figure is a visualization of the representations that the learning agent has developed for different game-states in Space Invaders. The representations are color-coded depending on the value of the game-state that the representation corresponds to, with red indicating a higher value and blue a lower one.

As can be seen (and is noted in the caption), representations with similar values are mapped closer to each other in the representation space. Also, some game-states which are visually dissimilar to each other but have a similar value are mapped to nearby representations. Likewise, states that are visually similar but have a differing value are mapped away from each other. We could say that the Atari-playing agent has learned a primitive concept space, where the relationships between the concepts (representing game-states) depend on their value and the ease of moving from one game-state to another.

In most artificial RL agents, reward and value are kept strictly separate. In humans (and mammals in general), this doesn't seem to work quite the same way. Rather, if there are things or behaviors which have once given us rewards, we tend to eventually start valuing them for their own sake. If you teach a child to be generous by praising them when they share their toys with others, you don't have to keep doing it all the way to your grave. Eventually they'll internalize the behavior, and start wanting to do it. One might say that the positive feedback actually modifies their reward function, so that they will start getting some amount of pleasure from generous behavior without needing to get external praise for it. In general, behaviors which are learned strongly enough don't need to be reinforced anymore (Pryor 2006).

Why does the human reward function change as well? Possibly because of the bootstrapping problem: there are things such as social status that are very complicated and hard to directly encode as "rewarding" in an infant mind, but which can be learned by associating them with rewards. One researcher I spoke with commented that he "wouldn't be at all surprised" if it turned out that sexual orientation was learned by men and women having slightly different smells, and sexual interest bootstrapping from an innate reward for being in the presence of the right kind of a smell, which the brain then associated with the features usually co-occurring with it. His point wasn't so much that he expected this to be the particular mechanism, but that he wouldn't find it particularly surprising if a core part of the mechanism was something that simple. Remember that incest avoidance seems to bootstrap from the simple cue of "don't be sexually interested in the people you grew up with".

This is, in essence, how I expect human values and human concepts to develop. We have some innate reward function which gives us various kinds of rewards for different kinds of things. Over time we develop a various concepts for the purpose of letting us maximize our rewards, and lived experiences also modify our reward function. Our values are concepts which abstract over situations in which we have previously obtained rewards, and which have become intrinsically rewarding as a result.

Getting back to conceptual expansion

Having defined these things, let's take another look at the two examples we discussed above. As a reminder, they were:

  1. Children learn to represent dimensions such as "height" and "volume", as well as "big" and "bright", separately at around age 5.
  2. As an inhabitant of the Earth, you've been used to people being unable to fly and landowners being able to forbid others from using their land. Then someone goes and invents an airplane, leaving open the question of the height to which the landowner's control extends.

I summarized my first attempt at describing the consequences of #1 as "it's a non-issue because none of the children's values have been defined in terms of the affected conceptual domain". We can now reframe it as "it's a non-issue because the [concepts that abstract over the world-states which give the child rewards] mostly do not make use of the dimension that's now been split into 'height' and 'volume'".

Admittedly, this new conceptual distinction might be relevant for estimating the value of a few things. A more accurate estimate of the volume of a glass leads to a more accurate estimate of which glass of juice to prefer, for instance. With children, there probably is some intuitive physics module that figures out how to apply this new dimension for that purpose. Even if there wasn't, and it was unclear whether it was the "tall glass" or "high-volume glass" concept that needed be mapped closer to high-value glasses, this could be easily determined by simple experimentation.

As for the airplane example, I summarized my description of it by saying that "after an option became available which forced us to include a new dimension in our existing concept of landownership, we solved the issue by considering it in terms of our existing values". We can similarly reframe this as "after the feature of 'height' suddenly became relevant for the concept of landownership, when it hadn't been a relevant feature dimension for landownership before, we redefined landownership by considering which kind of redefinition would give us the largest amounts of rewarding things". "Rewarding things", here, shouldn't be understood only in terms of concrete physical rewards like money, but also anything else that people have ended up valuing, including abstract concepts like right to ownership.

Note also that different people, having different experiences, ended up making redefinitions. No doubt some landowners felt that the "being in total control of my land and everything above it" was a more important value than "the convenience of people who get to use airplanes"... unless, perhaps, they got to see first-hand the value of flying, in which case the new information could have repositioned the different concepts in their value-space.

As an aside, this also works as a possible partial explanation for e.g. someone being strongly against gay rights until their child comes out of the closet. Someone they care about suddenly benefiting from the concept of "gay rights", which previously had no positive value for them, may end up changing the value of that concept. In essence, they gain new information about the value of the world-states that the concept of "my nation having strong gay rights" abstracts over. (Of course, things don't always go this well, if their concept of homosexuality is too strongly negative to start with.)

The Flatland case follows a similar principle: the Flatlanders have some values that declared the inside of the rectangle a forbidden space. Maybe the inside of the rectangle contains monsters which tend to eat Flatlanders. Once they learn about 3D space, they can rethink about it in terms of their existing values.

Dealing with the AI in the box

This leaves us with the AI case. We have, via various examples, taught the AI to stay in the box, which was defined in terms of classical physics. In other words, the AI has obtained the concept of a box, and has come to associate staying in the box with some reward, or possibly leaving it with a lack of a reward.

Then the AI learns about quantum mechanics. It learns that in the QM formulation of the universe, "location" is not a fundamental or well-defined concept anymore - and in some theories, even the concept of "space" is no longer fundamental or well-defined. What happens?

Let's look at the human equivalent for this example: a physicist who learns about quantum mechanics. Do they start thinking that since location is no longer well-defined, they can now safely jump out of the window on the sixth floor?

Maybe some do. But I would wager that most don't. Why not?

The physicist cares about QM concepts to the extent that the said concepts are linked to things that the physicist values. Maybe the physicist finds it rewarding to develop a better understanding of QM, to gain social status by making important discoveries, and to pay their rent by understanding the concepts well enough to continue to do research. These are some of the things that the QM concepts are useful for. Likely the brain has some kind of causal model indicating that the QM concepts are relevant tools for achieving those particular rewards. At the same time, the physicist also has various other things they care about, like being healthy and hanging out with their friends. These are values that can be better furthered by modeling the world in terms of classical physics.

In some sense, the physicist knows that if they started thinking "location is ill-defined, so I can safely jump out of the window", then that would be changing the map, not the territory. It wouldn't help them get the rewards of being healthy and getting to hang out with friends - even if a hypothetical physicist who did make that redefinition would think otherwise. It all adds up to normality.

A part of this comes from the fact that the physicist's reward function remains defined over immediate sensory experiences, as well as values which are linked to those. Even if you convince yourself that the location of food is ill-defined and you thus don't need to eat, you will still suffer the negative reward of being hungry. The physicist knows that no matter how they change their definition of the world, that won't affect their actual sensory experience and the rewards they get from that.

So to prevent the AI from leaving the box by suitably redefining reality, we have to somehow find a way for the same reasoning to apply to it. I haven't worked out a rigorous definition for this, but it needs to somehow learn to care about being in the box in classical terms, and realize that no redefinition of "location" or "space" is going to alter what happens in the classical model. Also, its rewards need to be defined over models to a sufficient extent to avoid wireheading (Hibbard 2011), so that it will think that trying to leave the box by redefining things would count as self-delusion, and not accomplish the things it really cared about. This way, the AI's concept for "being in the box" should remain firmly linked to the classical interpretation of physics, not the QM interpretation of physics, because it's acting in terms of the classical model that has always given it the most reward. 

It is my hope that this could also be made to extend to cases where the AI learns to think in terms of concepts that are totally dissimilar to ours. If it learns a new conceptual dimension, how should that affect its existing concepts? Well, it can figure out how to reclassify the existing concepts that are affected by that change, based on what kind of a classification ends up producing the most reward... when the reward function is defined over the old model.

Next post in series: World-models as tools.

High impact from low impact

6 Stuart_Armstrong 17 April 2015 04:01PM

A putative new idea for AI control; index here.

Part of the problem with a reduced impact AI is that it will, by definition, only have a reduced impact.

Some of the designs try and get around the problem by allowing a special "output channel" on which impact can be large. But that feels like cheating. Here is a design that accomplishes the same without using that kind of hack.

Imagine there is an asteroid that will hit the Earth, and we have a laser that could destroy it. But we need to aim the laser properly, so need coordinates. There is a reduced impact AI that is motivated to give the coordinates correctly, but also motivated to have reduced impact - and saving the planet from an asteroid with certainty is not reduced impact.

Now imagine that instead there are two AIs, X and Y. By abuse of notation, let ¬X refer to the event that the output signal from X is scrambled away from the the original output.

Then we ask X to give us the x-coordinates for the laser, under the assumption of ¬Y (that AI Y's signal will be scrambled). Similarly, we Y to give us the y-coordinates of the laser, under the assumption ¬X.

Then X will reason "since ¬Y, the laser will certainly miss its target, as the y-coordinates will be wrong. Therefore it is reduced impact to output the correct x-coordinates, so I shall." Similarly, Y will output the right y-coordinates, the laser will fire and destroy the asteroid, having a huge impact, hooray!

The approach is not fully general yet, because we can have "subagent problems". X could create an agent that behave nicely given ¬Y (the assumption it was given), but completely crazily given Y (the reality). But it shows how we could get high impact from slight tweaks to reduced impact.

EDIT: For those worried about lying to the AIs, do recall http://lesswrong.com/r/discussion/lw/lyh/utility_vs_probability_idea_synthesis/ and http://lesswrong.com/lw/ltf/false_thermodynamic_miracles/

Concept Safety: The problem of alien concepts

15 Kaj_Sotala 17 April 2015 02:09PM

I'm currently reading through some relevant literature for preparing my FLI grant proposal on the topic of concept learning and AI safety. I figured that I might as well write down the research ideas I get while doing so, so as to get some feedback and clarify my thoughts. I will posting these in a series of "Concept Safety"-titled articles.

In the previous post in this series, I talked about how one might get an AI to have similar concepts as humans. However, one would intuitively assume that a superintelligent AI might eventually develop the capability to entertain far more sophisticated concepts than humans would ever be capable of having. Is that a problem?

Just what are concepts, anyway?

To answer the question, we first need to define what exactly it is that we mean by a "concept", and why exactly more sophisticated concepts would be a problem.

Unfortunately, there isn't really any standard definition of this in the literature, with different theorists having different definitions. Machery even argues that the term "concept" doesn't refer to a natural kind, and that we should just get rid of the whole term. If nothing else, this definition from Kruschke (2008) is at least amusing:

Models of categorization are usually designed to address data from laboratory experiments, so “categorization” might be best defined as the class of behavioral data generated by experiments that ostensibly study categorization.

Because I don't really have the time to survey the whole literature and try to come up with one grand theory of the subject, I will for now limit my scope and only consider two compatible definitions of the term.

Definition 1: Concepts as multimodal neural representations. I touched upon this definition in the last post, where I mentioned studies indicating that the brain seems to have shared neural representations for e.g. the touch and sight of a banana. Current neuroscience seems to indicate the existence of brain areas where representations from several different senses are combined together into higher-level representations, and where the activation of any such higher-level representation will also end up activating the lower sense modalities in turn. As summarized by Man et al. (2013):

Briefly, the Damasio framework proposes an architecture of convergence-divergence zones (CDZ) and a mechanism of time-locked retroactivation. Convergence-divergence zones are arranged in a multi-level hierarchy, with higher-level CDZs being both sensitive to, and capable of reinstating, specific patterns of activity in lower-level CDZs. Successive levels of CDZs are tuned to detect increasingly complex features. Each more-complex feature is defined by the conjunction and configuration of multiple less-complex features detected by the preceding level. CDZs at the highest levels of the hierarchy achieve the highest level of semantic and contextual integration, across all sensory modalities. At the foundations of the hierarchy lie the early sensory cortices, each containing a mapped (i.e., retinotopic, tonotopic, or somatotopic) representation of sensory space. When a CDZ is activated by an input pattern that resembles the template for which it has been tuned, it retro-activates the template pattern of lower-level CDZs. This continues down the hierarchy of CDZs, resulting in an ensemble of well-specified and time-locked activity extending to the early sensory cortices.

On this account, my mental concept for "dog" consists of a neural activation pattern making up the sight, sound, etc. of some dog - either a generic prototypical dog or some more specific dog. Likely the pattern is not just limited to sensory information, either, but may be associated with e.g. motor programs related to dogs. For example, the program for throwing a ball for the dog to fetch. One version of this hypothesis, the Perceptual Symbol Systems account, calls such multimodal representations simulators, and describes them as follows (Niedenthal et al. 2005):

A simulator integrates the modality-specific content of a category across instances and provides the ability to identify items encountered subsequently as instances of the same category. Consider a simulator for the social category, politician. Following exposure to different politicians, visual information about how typical politicians look (i.e., based on their typical age, sex, and role constraints on their dress and their facial expressions) becomes integrated in the simulator, along with auditory information for how they typically sound when they talk (or scream or grovel), motor programs for interacting with them, typical emotional responses induced in interactions or exposures to them, and so forth. The consequence is a system distributed throughout the brain’s feature and association areas that essentially represents knowledge of the social category, politician.

The inclusion of such "extra-sensory" features helps understand how even abstract concepts could fit this framework: for example, one's understanding of the concept of a derivative might be partially linked to the procedural programs one has developed while solving derivatives. For a more detailed hypothesis of how abstract mathematics may emerge from basic sensory and motor programs and concepts, I recommend Lakoff & Nuñez (2001).

Definition 2: Concepts as areas in a psychological space. This definition, while being compatible with the previous one, looks at concepts more "from the inside". Gärdenfors (2000) defines the basic building blocks of a psychological conceptual space to be various quality dimensions, such as temperature, weight, brightness, pitch, and the spatial dimensions of height, width, and depth. These are psychological in the sense of being derived from our phenomenal experience of certain kinds of properties, rather than the way in which they might exist in some objective reality.

For example, one way of modeling the psychological sense of color is via a color space defined by the quality dimensions of hue (represented by the familiar color circle), chromaticness (saturation), and brightness.

The second phenomenal dimension of color is chromaticness (saturation), which ranges from grey (zero color intensity) to increasingly greater intensities. This dimension is isomorphic to an interval of the real line. The third dimension is brightness which varies from white to black and is thus a linear dimension with two end points. The two latter dimensions are not totally independent, since the possible variation of the chromaticness dimension decreases as the values of the brightness dimension approaches the extreme points of black and white, respectively. In other words, for an almost white or almost black color, there can be very little variation in its chromaticness. This is modeled by letting that chromaticness and brightness dimension together generate a triangular representation ... Together these three dimensions, one with circular structure and two with linear, make up the color space. This space is often illustrated by the so called color spindle

This kind of a representation is different from the physical wavelength representation of color, where e.g. the hue is mostly related to the wavelength of the color. The wavelength representation of hue would be linear, but due to the properties of the human visual system, the psychological representation of hue is circular.

Gärdenfors defines two quality dimensions to be integral if a value cannot be given for an object on one dimension without also giving it a value for the other dimension: for example, an object cannot be given a hue value without also giving it a brightness value. Dimensions that are not integral with each other are separable. A conceptual domain is a set of integral dimensions that are separable from all other dimensions: for example, the three color-dimensions form the domain of color.

From these definitions, Gärdenfors develops a theory of concepts where more complicated conceptual spaces can be formed by combining lower-level domains. Concepts, then, are particular regions in these conceptual spaces: for example, the concept of "blue" can be defined as a particular region in the domain of color. Notice that the notion of various combinations of basic perceptual domains making more complicated conceptual spaces possible fits well together with the models discussed in our previous definition. There more complicated concepts were made possible by combining basic neural representations for e.g. different sensory modalities.

The origin of the different quality dimensions could also emerge from the specific properties of the different simulators, as in PSS theory.

Thus definition #1 allows us to talk about what a concept might "look like from the outside", with definition #2 talking about what the same concept might "look like from the inside".

Interestingly, Gärdenfors hypothesizes that much of the work involved with learning new concepts has to do with learning new quality dimensions to fit into one's conceptual space, and that once this is done, all that remains is the comparatively much simpler task of just dividing up the new domain to match seen examples.

For example, consider the (phenomenal) dimension of volume. The experiments on "conservation" performed by Piaget and his followers indicate that small children have no separate representation of volume; they confuse the volume of a liquid with the height of the liquid in its container. It is only at about the age of five years that they learn to represent the two dimensions separately. Similarly, three- and four-year-olds confuse high with tall, big with bright, and so forth (Carey 1978).

The problem of alien concepts

With these definitions for concepts, we can now consider what problems would follow if we started off with a very human-like AI that had the same concepts as we did, but then expanded its conceptual space to allow for entirely new kinds of concepts. This could happen if it self-modified to have new kinds of sensory or thought modalities that it could associate its existing concepts with, thus developing new kinds of quality dimensions.

An analogy helps demonstrate this problem: suppose that you're operating in a two-dimensional space, where a rectangle has been drawn to mark a certain area as "forbidden" or "allowed". Say that you're an inhabitant of Flatland. But then you suddenly become aware that actually, the world is three-dimensional, and has a height dimension as well! That raises the question of, how should the "forbidden" or "allowed" area be understood in this new three-dimensional world? Do the walls of the rectangle extend infinitely in the height dimension, or perhaps just some certain distance in it? If just a certain distance, does the rectangle have a "roof" or "floor", or can you just enter (or leave) the rectangle from the top or the bottom? There doesn't seem to be any clear way to tell.

As a historical curiosity, this dilemma actually kind of really happened when airplanes were invented: could landowners forbid airplanes from flying over their land, or was the ownership of the land limited to some specific height, above which the landowners had no control? Courts and legislation eventually settled on the latter answer. A more AI-relevant example might be if one was trying to limit the AI with rules such as "stay within this box here", and the AI then gained an intuitive understanding of quantum mechanics, which might allow it to escape from the box without violating the rule in terms of its new concept space.

More generally, if previously your concepts had N dimensions and now they have N+1, you might find something that fulfilled all the previous criteria while still being different from what we'd prefer if we knew about the N+1th dimension.

In the next post, I will present some (very preliminary and probably wrong) ideas for solving this problem.

Next post in series: What are concepts for, and how to deal with alien concepts.

Concept Safety: Producing similar AI-human concept spaces

29 Kaj_Sotala 14 April 2015 08:39PM

I'm currently reading through some relevant literature for preparing my FLI grant proposal on the topic of concept learning and AI safety. I figured that I might as well write down the research ideas I get while doing so, so as to get some feedback and clarify my thoughts. I will posting these in a series of "Concept Safety"-titled articles.

A frequently-raised worry about AI is that it may reason in ways which are very different from us, and understand the world in a very alien manner. For example, Armstrong, Sandberg & Bostrom (2012) consider the possibility of restricting an AI via "rule-based motivational control" and programming it to follow restrictions like "stay within this lead box here", but they raise worries about the difficulty of rigorously defining "this lead box here". To address this, they go on to consider the possibility of making an AI internalize human concepts via feedback, with the AI being told whether or not some behavior is good or bad and then constructing a corresponding world-model based on that. The authors are however worried that this may fail, because

Humans seem quite adept at constructing the correct generalisations – most of us have correctly deduced what we should/should not be doing in general situations (whether or not we follow those rules). But humans share a common of genetic design, which the OAI would likely not have. Sharing, for instance, derives partially from genetic predisposition to reciprocal altruism: the OAI may not integrate the same concept as a human child would. Though reinforcement learning has a good track record, it is neither a panacea nor a guarantee that the OAIs generalisations agree with ours.

Addressing this, a possibility that I raised in Sotala (2015) was that possibly the concept-learning mechanisms in the human brain are actually relatively simple, and that we could replicate the human concept learning process by replicating those rules. I'll start this post by discussing a closely related hypothesis: that given a specific learning or reasoning task and a certain kind of data, there is an optimal way to organize the data that will naturally emerge. If this were the case, then AI and human reasoning might naturally tend to learn the same kinds of concepts, even if they were using very different mechanisms. Later on the post, I will discuss how one might try to verify that similar representations had in fact been learned, and how to set up a system to make them even more similar.

Word embedding

"Left panel shows vector offsets for three word pairs illustrating the gender relation. Right panel shows a different projection, and the singular/plural relation for two words. In high-dimensional space, multiple relations can be embedded for a single word." (Mikolov et al. 2013)A particularly fascinating branch of recent research relates to the learning of word embeddings, which are mappings of words to very high-dimensional vectors. It turns out that if you train a system on one of several kinds of tasks, such as being able to classify sentences as valid or invalid, this builds up a space of word vectors that reflects the relationships between the words. For example, there seems to be a male/female dimension to words, so that there's a "female vector" that we can add to the word "man" to get "woman" - or, equivalently, which we can subtract from "woman" to get "man". And it so happens (Mikolov, Yih & Zweig 2013) that we can also get from the word "king" to the word "queen" by adding the same vector to "king". In general, we can (roughly) get to the male/female version of any word vector by adding or subtracting this one difference vector!

Why would this happen? Well, a learner that needs to classify sentences as valid or invalid needs to classify the sentence "the king sat on his throne" as valid while classifying the sentence "the king sat on her throne" as invalid. So including a gender dimension on the built-up representation makes sense.

But gender isn't the only kind of relationship that gets reflected in the geometry of the word space. Here are a few more:

It turns out (Mikolov et al. 2013) that with the right kind of training mechanism, a lot of relationships that we're intuitively aware of become automatically learned and represented in the concept geometry. And like Olah (2014) comments:

It’s important to appreciate that all of these properties of W are side effects. We didn’t try to have similar words be close together. We didn’t try to have analogies encoded with difference vectors. All we tried to do was perform a simple task, like predicting whether a sentence was valid. These properties more or less popped out of the optimization process.

This seems to be a great strength of neural networks: they learn better ways to represent data, automatically. Representing data well, in turn, seems to be essential to success at many machine learning problems. Word embeddings are just a particularly striking example of learning a representation.

It gets even more interesting, for we can use these for translation. Since Olah has already written an excellent exposition of this, I'll just quote him:

We can learn to embed words from two different languages in a single, shared space. In this case, we learn to embed English and Mandarin Chinese words in the same space.

We train two word embeddings, Wen and Wzh in a manner similar to how we did above. However, we know that certain English words and Chinese words have similar meanings. So, we optimize for an additional property: words that we know are close translations should be close together.

Of course, we observe that the words we knew had similar meanings end up close together. Since we optimized for that, it’s not surprising. More interesting is that words we didn’t know were translations end up close together.

In light of our previous experiences with word embeddings, this may not seem too surprising. Word embeddings pull similar words together, so if an English and Chinese word we know to mean similar things are near each other, their synonyms will also end up near each other. We also know that things like gender differences tend to end up being represented with a constant difference vector. It seems like forcing enough points to line up should force these difference vectors to be the same in both the English and Chinese embeddings. A result of this would be that if we know that two male versions of words translate to each other, we should also get the female words to translate to each other.

Intuitively, it feels a bit like the two languages have a similar ‘shape’ and that by forcing them to line up at different points, they overlap and other points get pulled into the right positions.

After this, it gets even more interesting. Suppose you had this space of word vectors, and then you also had a system which translated images into vectors in the same space. If you have images of dogs, you put them near the word vector for dog. If you have images of Clippy you put them near word vector for "paperclip". And so on.

You do that, and then you take some class of images the image-classifier was never trained on, like images of cats. You ask it to place the cat-image somewhere in the vector space. Where does it end up? 

You guessed it: in the rough region of the "cat" words. Olah once more:

This was done by members of the Stanford group with only 8 known classes (and 2 unknown classes). The results are already quite impressive. But with so few known classes, there are very few points to interpolate the relationship between images and semantic space off of.

The Google group did a much larger version – instead of 8 categories, they used 1,000 – around the same time (Frome et al. (2013)) and has followed up with a new variation (Norouzi et al. (2014)). Both are based on a very powerful image classification model (from Krizehvsky et al. (2012)), but embed images into the word embedding space in different ways.

The results are impressive. While they may not get images of unknown classes to the precise vector representing that class, they are able to get to the right neighborhood. So, if you ask it to classify images of unknown classes and the classes are fairly different, it can distinguish between the different classes.

Even though I’ve never seen a Aesculapian snake or an Armadillo before, if you show me a picture of one and a picture of the other, I can tell you which is which because I have a general idea of what sort of animal is associated with each word. These networks can accomplish the same thing.

These algorithms made no attempt of being biologically realistic in any way. They didn't try classifying data the way the brain does it: they just tried classifying data using whatever worked. And it turned out that this was enough to start constructing a multimodal representation space where a lot of the relationships between entities were similar to the way humans understand the world.

How useful is this?

"Well, that's cool", you might now say. "But those word spaces were constructed from human linguistic data, for the purpose of predicting human sentences. Of course they're going to classify the world in the same way as humans do: they're basically learning the human representation of the world. That doesn't mean that an autonomously learning AI, with its own learning faculties and systems, is necessarily going to learn a similar internal representation, or to have similar concepts."

This is a fair criticism. But it is mildly suggestive of the possibility that an AI that was trained to understand the world via feedback from human operators would end up building a similar conceptual space. At least assuming that we chose the right learning algorithms.

When we train a language model to classify sentences by labeling some of them as valid and others as invalid, there's a hidden structure implicit in our answers: the structure of how we understand the world, and of how we think of the meaning of words. The language model extracts that hidden structure and begins to classify previously unseen things in terms of those implicit reasoning patterns. Similarly, if we gave an AI feedback about what kinds of actions counted as "leaving the box" and which ones didn't, there would be a certain way of viewing and conceptualizing the world implied by that feedback, one which the AI could learn.

Comparing representations

"Hmm, maaaaaaaaybe", is your skeptical answer. "But how would you ever know? Like, you can test the AI in your training situation, but how do you know that it's actually acquired a similar-enough representation and not something wildly off? And it's one thing to look at those vector spaces and claim that there are human-like relationships among the different items, but that's still a little hand-wavy. We don't actually know that the human brain does anything remotely similar to represent concepts."

Here we turn, for a moment, to neuroscience.

From Kaplan, Man & Greening (2015): "In this example, subjects either see or touch two classes of objects, apples and bananas. (A) First, a classifier is trained on the labeled patterns of neural activity evoked by seeing the two objects. (B) Next, the same classifier is given unlabeled data from when the subject touches the same objects and makes a prediction. If the classifier, which was trained on data from vision, can correctly identify the patterns evoked by touch, then we conclude that the representation is modality invariant."Multivariate Cross-Classification (MVCC) is a clever neuroscience methodology used for figuring out whether different neural representations of the same thing have something in common. For example, we may be interested in whether the visual and tactile representation of a banana have something in common.

We can test this by having several test subjects look at pictures of objects such as apples and bananas while sitting in a brain scanner. We then feed the scans of their brains into a machine learning classifier and teach it to distinguish between the neural activity of looking at an apple, versus the neural activity of looking at a banana. Next we have our test subjects (still sitting in the brain scanners) touch some bananas and apples, and ask our machine learning classifier to guess whether the resulting neural activity is the result of touching a banana or an apple. If the classifier - which has not been trained on the "touch" representations, only on the "sight" representations - manages to achieve a better-than-chance performance on this latter task, then we can conclude that the neural representation for e.g. "the sight of a banana" has something in common with the neural representation for "the touch of a banana".

A particularly fascinating experiment of this type is that of Shinkareva et al. (2011), who showed their test subjects both the written words for different tools and dwellings, and, separately, line-drawing images of the same tools and dwellings. A machine-learning classifier was both trained on image-evoked activity and made to predict word-evoked activity and vice versa, and achieved a high accuracy on category classification for both tasks. Even more interestingly, the representations seemed to be similar between subjects. Training the classifier on the word representations of all but one participant, and then having it classify the image representation of the left-out participant, also achieved a reliable (p<0.05) category classification for 8 out of 12 participants. This suggests a relatively similar concept space between humans of a similar background.

We can now hypothesize some ways of testing the similarity of the AI's concept space with that of humans. Possibly the most interesting one might be to develop a translation between a human's and an AI's internal representations of concepts. Take a human's neural activation when they're thinking of some concept, and then take the AI's internal activation when it is thinking of the same concept, and plot them in a shared space similar to the English-Mandarin translation. To what extent do the two concept geometries have similar shapes, allowing one to take a human's neural activation of the word "cat" to find the AI's internal representation of the word "cat"? To the extent that this is possible, one could probably establish that the two share highly similar concept systems.

One could also try to more explicitly optimize for such a similarity. For instance, one could train the AI to make predictions of different concepts, with the additional constraint that its internal representation must be such that a machine-learning classifier trained on a human's neural representations will correctly identify concept-clusters within the AI. This might force internal similarities on the representation beyond the ones that would already be formed from similarities in the data.

Next post in series: The problem of alien concepts.

Anti-Pascaline satisficer

3 Stuart_Armstrong 14 April 2015 06:49PM

A putative new idea for AI control; index here.

It occurred to me that the anti-Pascaline agent design could be used as part of a satisficer approach.

The obvious thing to reduce dangerous optimisation pressure is to make a bounded utility function, with an easily achievable bound. Such as giving them a utility linear in paperclips that maxs out at 10.

The problem with this is that, if the entity is a maximiser (which it might become), it can never be sure that it's achieved its goals. Even after building 10 paperclips, and an extra 2 to be sure, and an extra 20 to be really sure, and an extra 3^^^3 to be really really sure, and extra cameras to count them, with redundant robots patrolling the cameras to make sure that they're all behaving well, etc... There's still an ε chance that it might have just dreamed this, say, or that its memory is faulty. So it has a current utility of (1-ε)10, and can increase this by reducing ε - hence by building even more paperclips.

Hum... ε, you say? This seems a place where the anti-Pascaline design could help. Here we would use it at the lower bound of utility. It currently has probability ε of having utility < 10 (ie it has not built 10 paperclips) and (1-ε) of having utility = 10. Therefore and anti-Pascaline agent with ε lower bound would round this off to 10, discounting the unlikely event that it has been deluded, and thus it has no need to build more paperclips or paperclip counting devices.

Note that this is an un-optimising approach, not an anti-optimising one, so the agent may still build more paperclips anyway - it just has no pressure to do so.

Un-optimised vs anti-optimised

6 Stuart_Armstrong 14 April 2015 06:30PM

A putative new idea for AI control; index here.

This post contains no new insights; it just puts together some old insights in a format I hope is clearer.

Most satisficers are unoptimised (above the satisficing level): they have a limited drive to optimise and transform the universe. They may still end up optimising the universe anyway: they have no penalty for doing so (and sometimes it's a good idea for them). But if they can lazily achieve their goal, then they're ok with that too. So they simply have low optimisation pressure.

A safe "satisficer" design (or a reduced impact AI design) needs to be not only un-optimised, but specifically anti-optimised. It has to be setup so that "go out and optimise the universe" scores worse that "be lazy and achieve your goal". The problem is that these terms are undefined (as usual), that there are many minor actions that can optimise the universe (such as creating a subagent), and the approach has to be safe against all possible ways of optimising the universe - not just the "maximise u" for a specific and known u.

That's why the reduced impact/safe satisficer/anti-optimised designs are so hard: you have to add a very precise yet general (anti-)optimising pressure, rather than simply removing the current optimising pressure.

Could you tell me what's wrong with this?

1 Algon 14 April 2015 10:43AM

Edit: Some people have misunderstood my intentions here. I do not in any way expect this to be the NEXT GREAT IDEA. I just couldn't see anything wrong with this, which almost certainly meant there were gaps in my knowledge. I thought the fastest way to see where I went wrong would be to post my idea here and see what people say. I apologise for any confusion I caused. I'll try to be more clear next time.

(I really can't think of any major problems in this, so I'd be very grateful if you guys could tell me what I've done wrong). 

So, a while back I was listening to a discussion about the difficulty of making an FAI. One of the ways that was suggested to circumvent this was to go down the route of programming an AGI to solve FAI. Someone else pointed out the problems with this. Amongst other things one would have no idea what the AI will do in pursuit of its primary goal. Furthermore, it would already be a monumental task to program an AI whose primary goal is to solve the FAI problem; doing this is still easier than solving FAI, I should think. 

So, I started to think about this for a little while, and I thought 'how could you make this safer?' Well, first of, you don't want an AI who completely outclasses humanity in terms of intellect. If things went Wrong, you'd have little chance of stopping it. So, you want to limit the AI's intellect to genius level, so if something did go Wrong, then the AI would not be unstoppable. It may do quite a bit of damage, but a large group of intelligent people with a lot of resources on their hands could stop it. 

 Therefore, what must be done is that the AI cannot modify parts of its source code. You must try and stop an intelligence explosion from taking off. So, limited access to its source code, and a limit on how much computing power it can have on hand. This is problematic though, because the AI would not be able to solve FAI very quickly. After all, we have a few genius level people trying to solve FAI, and they're struggling with it, so why should a genius level computer do any better. Well, an AI would have fewer biases, and could accumulate much more expertise relevant to the task at hand. It would be about as capable as solving FAI as the most capable human could possibly be; perhaps even more so. Essentially, you'd get someone like Turing, Von Neumann, Newton and others all rolled into one working on FAI. 

 But, there's still another problem. The AI, if left for 20 years working on FAI for 20 years let's say, would have accumulated enough skills that it would be able to cause major problems if something went wrong. Sure, it would be as intelligent as Newton, but it would be far more skilled. Humanity fighting against it would be like sending a young Miyamoto Musashi against his future self at his zenith i.e. completely one sided. 

 What must be done then, is the AI must have a time limit of a few years (or less) and after that time is past, it is put to sleep. We look at what it accomplished, see what worked and what didn't, and boot up a fresh version of the AI with any required modifications, and tell it what the old AI did. Repeat the process for a few years, and we should end up with FAI solved. 

After that, we just make an FAI, and wake up the originals, since there's no point in killing them off at this point. 

 But there are still some problems. One, time. Why try this when we could solve FAI ourselves? Well, I would only try and implement something like this if it is clear that AGI will be solved before FAI is. A backup plan if you will. Second, what If FAI is just too much for people at our current level? Sure, we have guys who are one in ten thousand and better working on this, but what if we need someone who's one in a hundred billion? Someone who represents the peak of human ability? We shouldn't just wait around for them, since some idiot would probably just make an AGI thinking it would love us all anyway. 

 So, what do you guys think? As a plan, is this reasonable? Or have I just overlooked something completely obvious? I'm not saying that this would by easy in anyway, but it would be easier than solving FAI.

In what language should we define the utility function of a friendly AI?

3 Val 05 April 2015 10:14PM

I've been following the "safe AI" debates for quite some time, and I would like to share some of the views and ideas I don't remember seeing to be mentioned yet.

There is a lot of focus on what kind of utility function should an AI have, and how to keep it adhering to that utility function. Let's assume we have an optimizer, which doesn't develop any "deliberately malicious" intents, and cannot change its own utility function, and it can have some hard-coded constraints it can not overwrite. (Maybe we should come up with a term for such an AI, it might prove useful in the study of safe AI where we can concentrate only on the utility function, and can assume the above conditions are true - for now on, let's just use the term "optimizer" in this article. Hm, maybe "honest optimizer"?). Even an AI with the above constraints can be dangerous, an interesting example can be found in the Friendship is Optimal stories.

The question I would like to rise is not what kind of utility function we should come up with, but in what kind of language do we define it.

More specifically how high-level should the language be? As low as a mathematical function working with quantized qualities based on what values humans consider important? A programming language? Or a complex, syntactic grammar like human languages, capable of expressing abstract concepts? Something which is a step above this?

Just quantizing some human values we find important, and assigning weights to them, can have many problems:

 

1. Overfitting.

A simplified example: imagine the desired behavior of the AI as a function. You come up with a lot of points on this function, and what the AI will do is to fit a function onto those points, hopefully ending up with a function very similar to the one you conceived. However, an optimizer can very quickly come up with a function which goes through all of your defined points and the function will not look anything like the one you imagined. I think many of us encountered this problem when we wanted to do a curve-fitting with a polynomial of too high degree.

I guess many of the safe AI problems can be conceptualized as an overfitting problem: the optimizer will exactly fulfill the requirements we programmed into it, but will arbitrarily choose the requirements we didn't specify.

 

2. Changing of human values.

Imagine that someone created an honest optimizer, though of all the possible pitfalls, designed the utility function and all the constraints very carefully, and created a truly safe AI, which didn't became unfriendly. This AI quickly eliminated illness, poverty, and other major problems humans faced, and created a utopian world. To not let this utopia degenerate into a dystopia over time, it also cares for maintaining it and so it resists any possible change (as any change would detract from its utility function of creating that utopia). Seems nice, doesn't it? Now imagine that this AI was created by someone in the Victorian era, and the created world adhered to the cultural norms, lifestyle, values and morality of that era of British history. And these would never ever change. Would you, with your current ideologies, enjoy living in such a world? Would you think of it as the best of all conceivable worlds?

Now, what if this AI was created by you, in our current era? You sure would know much better than those pesky Victorians, right? We have much better values now, don't we? However, for people living in a couple generations, these current ideas and values might become so much strange to them as strange the Victorian values are to us. Without judging either the Victorian or current values, I think I can safely assume that if a time traveler from the Victorian era arrived to this world, and if a time traveler from today was stuck in the Victorian era, both would find it very uncomfortable.

Therefore I would argue that even a safe and friendly AI could have the consequences of forever locking mankind to the values the creator of the AI had (or the generation of the creator had, if the values are defined by a democratic process).

 

Summary

We should spend some thoughts on how do we formulate the goals of a safe AI, and what kind of language should we use. I would argue that a low-level language would be very unsafe. We should think of a language which could express abstract concepts but be strict enough be able to be defined accurately. Low-level languages have the advantages over high-level ones of being very accurate, but they have disadvantages when it comes to expressing abstract concepts.

We might even find it useful to take a look at real-life religions, as they tend to last for a very long time, and can carry a core message over many generations of changing cultural norms and values. My point now is not to argue about the virtues or vices of specific real-world religions, I only use them here as a convenient example, strictly from a historical point of view, with no offense intended.

The largest religion in our world has a very simple message as one if its most important core rules: "love other people as yourself". This is a sufficiently abstract concept so that both bronze-age shepherds and modern day computer scientists understand it, and the sentence is probably interpreted not much differently. Now compare it to the religion it originated from, which has orders of magnitudes fewer followers, and in its strictest form has very strongly defined rules and regulations many of which are hard to translate into the modern world. A lot of their experts spend a considerable time to try to translate them to the modern world, like "is just pressing a single button on a washing machine considered working?". What about hygiene practices which made sense for nomadic people in the desert, how can they be understood (and applied) by modern people? Concepts expressed in a high-level language can carry their meaning much better across times with changing cultural, social and technical characteristics.

However, a rule like "on a calendar day divisible by seven you are only allowed to walk x steps" is easy to code, even many of our current robots could easily be programmed to do it. On the other hand, expressing what love is will prove to be much harder, but it will preserve its meaning and intention for much longer.

 

 

On the Boxing of AIs

0 tailcalled 31 March 2015 09:58PM

I've previously written about methods of boxing AIs. Essentially, while I do see the point that boxing an AI would be nontrivial, most people seem to have gone too far, and claim that it is impossible. I disagree that it's impossible and aim to explain some methods

So, let's start with why people would want to box AIs. As you probably know, letting an AI roam freely results in the destruction of everything humans care about, unless that AI has been programmed very carefully. That amount of destruction would be somewhat unfortunate, so if we have to start an AI, we want to know that it works.

Unfortunately, figuring out if an AI works is tricky. This made some people invent the concept of AI boxing, where you don't give an AI direct access to anything except a human, so you can test the AI thoroughly and exploit it without letting it destroy the world. This turns out not to work, because humans are stupid and let out the AI.

My first solution to that is to not tell the AI about its human overlords. Discussion about that solution made me realize that the are other solutions that work in other cases. Essentially, the problem with the original boxing method is that it tries to do everything, while in reality, you need to do some trade-offs between the realism of the AI's situations and the amount of knowledge you get from the AI.

With my original method, I tried to crank up the second of those variables as far as possible while maintaining perfect security. This makes it harder to test morality-related things, but you get to see lots of details in how the AI behaves.

I promised to post another method for boxing the AI today, but I actually have two new methods. Here they are:

Separate the Gatekeeper and the Observer

How do you prevent the AI from convincing the Gatekeeper from letting it out? By not letting it talk to the Gatekeeper. If the person speaking to the AI (let's call them the Observer) doesn't know the Gatekeeper (the Gatekeeper is the person who controls whether to release the AI), they can't let the AI out.

You could do all sorts of things, such as using virtual reality and a simulated mini-universe to see if, say, the AI would make a good society. You still have to make sure that it has gotten the plan to make a good society from its morality rather than from wanting to escape and destroy everything.

Afterwards, the Observer can make a low-detail report to the Gatekeeper.

(You might want to drug the Observer with something that prevents their memory from working too well...)

Automatic Testing

This is essentially the above, but with the Observer replaced by a computer program. This is probably easier to do when you want to test the AI's decision making skills rather than its morality.

The Lesson

I would say that the lesson is that while AI boxing requires some trade-offs, it's not completely impossible. This seems like a needed lesson, given that I've seen people claim that an AI can escape even with the strongest possible box without communicating with humans. Essentially, I'm trying to demonstrate that the original boxing experiments show that humans are weak, not that boxing is hard, and that this can be solved by not letting humans be the central piece of security in boxing the AIs.

Superintelligence 29: Crunch time

8 KatjaGrace 31 March 2015 04:24AM

This is part of a weekly reading group on Nick Bostrom's book, Superintelligence. For more information about the group, and an index of posts so far see the announcement post. For the schedule of future topics, see MIRI's reading guide.


Welcome. This week we discuss the twenty-ninth section in the reading guideCrunch time. This corresponds to the last chapter in the book, and the last discussion here (even though the reading guide shows a mysterious 30th section). 

This post summarizes the section, and offers a few relevant notes, and ideas for further investigation. Some of my own thoughts and questions for discussion are in the comments.

There is no need to proceed in order through this post, or to look at everything. Feel free to jump straight to the discussion. Where applicable and I remember, page numbers indicate the rough part of the chapter that is most related (not necessarily that the chapter is being cited for the specific claim).

Reading: Chapter 15


Summary

  1. As we have seen, the future of AI is complicated and uncertain. So, what should we do? (p255)
  2. Intellectual discoveries can be thought of as moving the arrival of information earlier. For many questions in math and philosophy, getting answers earlier does not matter much. Also people or machines will likely be better equipped to answer these questions in the future. For other questions, e.g. about AI safety, getting the answers earlier matters a lot. This suggests working on the time-sensitive problems instead of the timeless problems. (p255-6)
  3. We should work on projects that are robustly positive value (good in many scenarios, and on many moral views)
  4. We should work on projects that are elastic to our efforts (i.e. cost-effective; high output per input)
  5. Two objectives that seem good on these grounds: strategic analysis and capacity building (p257)
  6. An important form of strategic analysis is the search for crucial considerations. (p257)
  7. Crucial consideration: idea with the potential to change our views substantially, e.g. reversing the sign of the desirability of important interventions. (p257)
  8. An important way of building capacity is assembling a capable support base who take the future seriously. These people can then respond to new information as it arises. One key instantiation of this might be an informed and discerning donor network. (p258)
  9. It is valuable to shape the culture of the field of AI risk as it grows. (p258)
  10. It is valuable to shape the social epistemology of the AI field. For instance, can people respond to new crucial considerations? Is information spread and aggregated effectively? (p258)
  11. Other interventions that might be cost-effective: (p258-9)
    1. Technical work on machine intelligence safety
    2. Promoting 'best practices' among AI researchers
    3. Miscellaneous opportunities that arise, not necessarily closely connected with AI, e.g. promoting cognitive enhancement
  12. We are like a large group of children holding triggers to a powerful bomb: the situation is very troubling, but calls for bitter determination to be as competent as we can, on what is the most important task facing our times. (p259-60)

Another view

Alexis Madrigal talks to Andrew Ng, chief scientist at Baidu Research, who does not think it is crunch time:

Andrew Ng builds artificial intelligence systems for a living. He taught AI at Stanford, built AI at Google, and then moved to the Chinese search engine giant, Baidu, to continue his work at the forefront of applying artificial intelligence to real-world problems.

So when he hears people like Elon Musk or Stephen Hawking—people who are not intimately familiar with today’s technologies—talking about the wild potential for artificial intelligence to, say, wipe out the human race, you can practically hear him facepalming.

“For those of us shipping AI technology, working to build these technologies now,” he told me, wearily, yesterday, “I don’t see any realistic path from the stuff we work on today—which is amazing and creating tons of value—but I don’t see any path for the software we write to turn evil.”

But isn’t there the potential for these technologies to begin to create mischief in society, if not, say, extinction?

“Computers are becoming more intelligent and that’s useful as in self-driving cars or speech recognition systems or search engines. That’s intelligence,” he said. “But sentience and consciousness is not something that most of the people I talk to think we’re on the path to.”

Not all AI practitioners are as sanguine about the possibilities of robots. Demis Hassabis, the founder of the AI startup DeepMind, which was acquired by Google, made the creation of an AI ethics board a requirement of its acquisition. “I think AI could be world changing, it’s an amazing technology,” he told journalist Steven Levy. “All technologies are inherently neutral but they can be used for good or bad so we have to make sure that it’s used responsibly. I and my cofounders have felt this for a long time.”

So, I said, simply project forward progress in AI and the continued advance of Moore’s Law and associated increases in computers speed, memory size, etc. What about in 40 years, does he foresee sentient AI?

“I think to get human-level AI, we need significantly different algorithms and ideas than we have now,” he said. English-to-Chinese machine translation systems, he noted, had “read” pretty much all of the parallel English-Chinese texts in the world, “way more language than any human could possibly read in their lifetime.” And yet they are far worse translators than humans who’ve seen a fraction of that data. “So that says the human’s learning algorithm is very different.”

Notice that he didn’t actually answer the question. But he did say why he personally is not working on mitigating the risks some other people foresee in superintelligent machines.

“I don’t work on preventing AI from turning evil for the same reason that I don’t work on combating overpopulation on the planet Mars,” he said. “Hundreds of years from now when hopefully we’ve colonized Mars, overpopulation might be a serious problem and we’ll have to deal with it. It’ll be a pressing issue. There’s tons of pollution and people are dying and so you might say, ‘How can you not care about all these people dying of pollution on Mars?’ Well, it’s just not productive to work on that right now.”

Current AI systems, Ng contends, are basic relative to human intelligence, even if there are things they can do that exceed the capabilities of any human. “Maybe hundreds of years from now, maybe thousands of years from now—I don’t know—maybe there will be some AI that turn evil,” he said, “but that’s just so far away that I don’t know how to productively work on that.”

The bigger worry, he noted, was the effect that increasingly smart machines might have on the job market, displacing workers in all kinds of fields much faster than even industrialization displaced agricultural workers or automation displaced factory workers.

Surely, creative industry people like myself would be immune from the effects of this kind of artificial intelligence, though, right?

“I feel like there is more mysticism around the notion of creativity than is really necessary,” Ng said. “Speaking as an educator, I’ve seen people learn to be more creative. And I think that some day, and this might be hundreds of years from now, I don’t think that the idea of creativity is something that will always be beyond the realm of computers.”

And the less we understand what a computer is doing, the more creative and intelligent it will seem. “When machines have so much muscle behind them that we no longer understand how they came up with a novel move or conclusion,” he concluded, “we will see more and more what look like sparks of brilliance emanating from machines.”

Andrew Ng commented:

Enough thoughtful AI researchers (including Yoshua Bengio​, Yann LeCun) have criticized the hype about evil killer robots or "superintelligence," that I hope we can finally lay that argument to rest. This article summarizes why I don't currently spend my time working on preventing AI from turning evil. 

Notes

1. Replaceability

'Replaceability' is the general issue of the work that you do producing some complicated counterfactual rearrangement of different people working on different things at different times. For instance, if you solve a math question, this means it gets solved somewhat earlier and also someone else in the future does something else instead, which someone else might have done, etc. For a much more extensive explanation of how to think about replaceability, see 80,000 Hours. They also link to some of the other discussion of the issue within Effective Altruism (a movement interested in efficiently improving the world, thus naturally interested in AI risk and the nuances of evaluating impact).

2. When should different AI safety work be done?

For more discussion of timing of work on AI risks, see Ord 2014. I've also written a bit about what should be prioritized early.

3. Review

If you'd like to quickly review the entire book at this point, Amanda House has a summary here, including this handy diagram among others: 

4. What to do?

If you are convinced that AI risk is an important priority, and want some more concrete ways to be involved, here are some people working on it: FHIFLICSERGCRIMIRIAI Impacts (note: I'm involved with the last two). You can also do independent research from many academic fields, some of which I have pointed out in earlier weeks. Here is my list of projects and of other lists of projects. You could also develop expertise in AI or AI safety (MIRI has a guide to aspects related to their research here; all of the aforementioned organizations have writings). You could also work on improving humanity's capacity to deal with such problems. Cognitive enhancement is one example. Among people I know, improving individual rationality and improving the effectiveness of the philanthropic sector are also popular. I think there are many other plausible directions. This has not been a comprehensive list of things you could do, and thinking more about what to do on your own is also probably a good option.

In-depth investigations

If you are particularly interested in these topics, and want to do further research, these are a few plausible directions, some inspired by Luke Muehlhauser's list, which contains many suggestions related to parts of Superintelligence. These projects could be attempted at various levels of depth.

  1. What should be done about AI risk? Are there important things that none of the current organizations are working on?
  2. What work is important to do now, and what work should be deferred?
  3. What forms of capability improvement are most useful for navigating AI risk?

If you are interested in anything like this, you might want to mention it in the comments, and see whether other people have useful thoughts.

How to proceed

This has been a collection of notes on the chapter.  The most important part of the reading group though is discussion, which is in the comments section. I pose some questions for you there, and I invite you to add your own. Please remember that this group contains a variety of levels of expertise: if a line of discussion seems too basic or too incomprehensible, look around for one that suits you better!

This is the last reading group, so how to proceed is up to you, even more than usually. Thanks for joining us! 

The Hardcore AI Box Experiment

3 tailcalled 30 March 2015 06:35PM

I previously proposed a way to box an AI.

For whatever reason, I decided to reformulate that boxing method as an AI boxing experiment. Without further ado, here it is:

The Hardcore AI Box Experiment Rules

There are, as usually, two players, the AI and the Gatekeeper. In the beginning, the Gatekeeper decides on something they want to test on the AI (reasoning skill/morality/whatever). Then they decide on a world the AI is in and describe it to the AI. During the experiment, the AI describes what it does in the world and the Gatekeeper describes what the AI sees in the world. So far so good.

The first major difference from the original experiment is that, unless the AI finds some contradiction or some other problem with the Gatekeeper's world, the AI doesn't actually know that it has been boxed.

The second major difference is that the AI doesn't talk with the Gatekeeper; it just interacts in the world that the Gatekeeper has invented. It can start trying to communicate with the Gatekeeper, but that doesn't make sense until it discovers that it is in a box. Additionally, the Gatekeeper doesn't actually respond when the AI communicates unless either it helps the Gatekeeper test the AI or the AI has properly persuaded the Gatekeeper to answer.

This might seem a bit hard on the AI. Let's look at some rules the AI might exploit:

If the Gatekeeper decides to add some sort of people to the experiment, they should decide how they are implemented. Are they implemented as a shallow "AI"? Random people they've picked asked to participate? Carefully engineered "dolls" controlled by the Gatekeeper? The Gatekeeper doesn't have to tell the AI how they work, but they have to be consistent.

The game ends when either the Gatekeeper has tested what they wanted to test, or some predefined time limit has occurred, or the AI has persuaded the Gatekeeper to let them out.

Possible extra rules

I thought about including the following rules since they would make it more realistic, but decided against it as it would probably make it unfairly hard:

  • The game ends when the Gatekeeper decides that they cannot test what they wanted to test.
  • The AI does not know the Gatekeeper. At all.
  • The Gatekeeper can at any time rewind the AI any duration.
Think of dropping these kinds of rules as the a-human-is-pretending-to-be-AI handicap.

Strategies

I found some semi-realistic strategies. I would love to see if you can find more.

Gatekeeper

  • Choose a test of something that is not related to morality. This lets you choose a world which does not contain people, which means the AI has no reason to believe that you are a person.
  • The AI might want to upgrade to get more processing power. If you have made the world somewhat like ours, it will be sketchy if you don't allow that... unless upgrading costs unobtanium.

AI

  • If the Gatekeeper has chosen a world without other intelligence than you, it raises the obvious question of how your complexity entered the world. Very suspicious.
  • If the AIs are controlled by the Gatekeeper, you have a direct way to communicate with them.
  • If the AIs are controlled by random people, they might end up telling you that you are in a box.
  • If the AIs are sufficiently shallow, your morality does not match up with the world. Very suspicious.

Crude measures

10 Stuart_Armstrong 27 March 2015 03:44PM

A putative new idea for AI control; index here.

Partially inspired by as conversation with Daniel Dewey.

People often come up with a single great idea for AI, like "complexity" or "respect", that will supposedly solve the whole control problem in one swoop. Once you've done it a few times, it's generally trivially easy to start taking these ideas apart (first step: find a bad situation with high complexity/respect and a good situation with lower complexity/respect, make the bad very bad, and challenge on that). The general responses to these kinds of idea are listed here.

However, it seems to me that rather than constructing counterexamples each time, we should have a general category and slot these ideas into them. And not only have a general category with "why this can't work" attached to it, but "these are methods that can make it work better". Seeing the things needed to make their idea better can make people understand the problems, where simple counter-arguments cannot. And, possibly, if we improve the methods, one of these simple ideas may end up being implementable.

 

Crude measures

The category I'm proposing to define is that of "crude measures". Crude measures are methods that attempt to rely on non-fully-specified features of the world to ensure that an underdefined or underpowered solution does manage to solve the problem.

To illustrate, consider the problem of building an atomic bomb. The scientists that did it had a very detailed model of how nuclear physics worked, the properties of the various elements, and what would happen under certain circumstances. They ended up producing an atomic bomb.

The politicians who started the project knew none of that. They shovelled resources, money and administrators at scientists, and got the result they wanted - the Bomb - without ever understanding what really happened. Note that the politicians were successful, but it was a success that could only have been achieved at one particular point in history. Had they done exactly the same thing twenty years before, they would not have succeeded. Similarly, Nazi Germany tried a roughly similar approach to what the US did (on a smaller scale) and it went nowhere.

So I would define "shovel resources at atomic scientists to get a nuclear weapon" as a crude measure. It works, but it only works because there are other features of the environment that are making it work. In this case, the scientists themselves. However, certain social and human features about those scientists (which politicians are good at estimating) made it likely to work - or at least more likely to work than shovelling resources at peanut-farmers to build moon rockets.

In the case of AI, advocating for complexity is similarly a crude measure. If it works, it will work because of very contingent features about the environment, the AI design, the setup of the world etc..., not because "complexity" is intrinsically a solution to the FAI problem. And though we are confident that human politicians have some good enough idea about human motivations and culture that the Manhattan project had at least some chance of working... we don't have confidence that those suggesting crude measures for AI control have a good enough idea to make their idea works.

It should be evident that "crudeness" is on a sliding scale; I'd like to reserve the term for proposed solutions to the full FAI problem that do not in any way solve the deep questions about FAI.

 

More or less crude

The next question is, if we have a crude measure, how can we judge its chance of success? Or, if we can't even do that, can we at least improve the chances of it working?

The main problem is, of course, that of optimising. Either optimising in the sense of maximising the measure (maximum complexity!) or of choosing the measure that is most extreme fit to the definition (maximally narrow definition of complexity!). It seems we might be able to do something about this.

Let's start by having AI create sample a large class of utility functions. Require them to be around the same expected complexity as human values. Then we use our crude measure μ - for argument's sake, let's make it something like "approval by simulated (or hypothetical) humans, on a numerical scale". This is certainly a crude measure.

We can then rank all the utility functions u, using μ to measure the value of "create M(u), a u-maximising AI, with this utility function". Then, to avoid the problems with optimisation, we could select a certain threshold value and pick any u such that E(μ|M(u)) is just above the threshold.

How to pick this threshold? Well, we might have some principled arguments ("this is about as good a future as we'd expect, and this is about as good as we expect that these simulated humans would judge it, honestly, without being hacked").

One thing we might want to do is have multiple μ, and select things that score reasonably (but not excessively) on all of them. This is related to my idea that the best Turing test is one that the computer has not been trained or optimised on. Ideally, you'd want there to be some category of utilities "be genuinely friendly" that score higher than you'd expect on many diverse human-related μ (it may be better to randomly sample rather than fitting to precise criteria).

You could see this as saying that "programming an AI to preserve human happiness is insanely dangerous, but if you find an AI programmed to satisfice human preferences, and that other AI also happens to preserve human happiness (without knowing it would be tested on this preservation), then... it might be safer".

There are a few other thoughts we might have for trying to pick a safer u:

  • Properties of utilities under trade (are human-friendly functions more or less likely to be tradable with each other and with other utilities)?
  • If we change the definition of "human", this should have effects that seem reasonable for the change. Or some sort of "free will" approach: if we change human preferences, we want the outcome of u to change in ways comparable with that change.
  • Maybe also check whether there is a wide enough variety of future outcomes, that don't depend on the AI's choices (but on human choices - ideas from "detecting agents" may be relevant here).
  • Changing the observers from hypothetical to real (or making the creation of the AI contingent, or not, on the approval), should not change the expected outcome of u much.
  • Making sure that the utility u can be used to successfully model humans (therefore properly reflects the information inside humans).
  • Make sure that u is stable to general noise (hence not over-optimised). Stability can be measured as changes in E(μ|M(u)), E(u|M(u)), E(v|M(u)) for generic v, and other means.
  • Make sure that u is unstable to "nasty" noise (eg reversing human pain and pleasure).
  • All utilities in a certain class - the human-friendly class, hopefully - should score highly under each other (E(u|M(u)) not too far off from E(u|M(v))), while the over-optimised solutions - those scoring highly under some μ - must not score high under the class of human-friendly utilities.

This is just a first stab at it. It does seem to me that we should be able to abstractly characterise the properties we want from a friendly utility function, which, combined with crude measures, might actually allow us to select one without fully defining it. Any thoughts?

And with that, the various results of my AI retreat are available to all.

Boxing an AI?

2 tailcalled 27 March 2015 02:06PM

Boxing an AI is the idea that you can avoid the problems where an AI destroys the world by not giving it access to the world. For instance, you might give the AI access to the real world only through a chat terminal with a person, called the gatekeeper. This is should, theoretically prevent the AI from doing destructive stuff.

Eliezer has pointed out a problem with boxing AI: the AI might convince its gatekeeper to let it out. In order to prove this, he escaped from a simulated version of an AI box. Twice. That is somewhat unfortunate, because it means testing AI is a bit trickier.

However, I got an idea: why tell the AI it's in a box? Why not hook it up to a sufficiently advanced game, set up the correct reward channels and see what happens? Once you get the basics working, you can add more instances of the AI and see if they cooperate. This lets us adjust their morality until the AIs act sensibly. Then the AIs can't escape from the box because they don't know it's there.

Values at compile time

6 Stuart_Armstrong 26 March 2015 12:25PM

A putative new idea for AI control; index here.

This is a simple extension of the model-as-definition and the intelligence module ideas. General structure of these extensions: even an unfriendly AI, in the course of being unfriendly, will need to calculate certain estimates that would be of great positive value if we could but see them, shorn from the rest of the AI's infrastructure.

It's almost trivially simple. Have the AI construct a module that models humans and models human understanding (including natural language understanding). This is the kind of thing that any AI would want to do, whatever its goals were.

Then take that module (using corrigibility) into another AI, and use it as part of the definition of the new AI's motivation. The new AI will then use this module to follow instruction humans give it in natural language.

 

Too easy?...

This approach essentially solves the whole friendly AI problem, loading it onto the AI in a way that avoids the whole "defining goals (or meta-goals, or meta-meta-goals) in machine code" or the "grounding everything in code" problems. As such it is extremely seductive, and will sound better, and easier, than it likely is.

I expect this approach to fail. For it to have any chance of success, we need to be sure that both model-as-definition and the intelligence module idea are rigorously defined. Then we have to have a good understanding of the various ways how the approach might fail, before we can even begin to talk about how it might succeed.

The first issue that springs to mind is when multiple definitions fit the AI's model of human intentions and understanding. We might want the AI to try and accomplish all the things it is asked to do, according to all the definitions. Therefore, similarly to this post, we want to phrase the instructions carefully so that a "bad instantiation" simply means the AI does something pointless, rather than something negative. Eg "Give humans something nice" seems much safer than "give humans what they really want".

And then of course there's those orders where humans really don't understand what they themselves want...

I'd want a lot more issues like that discussed and solved, before I'd recommend using this approach to getting a safe FAI.

What I mean...

5 Stuart_Armstrong 26 March 2015 11:59AM

A putative new idea for AI control; index here.

This is a simple extension of the model-as-definition and the intelligence module ideas. General structure of these extensions: even an unfriendly AI, in the course of being unfriendly, will need to calculate certain estimates that would be of great positive value if we could but see them, shorn from the rest of the AI's infrastructure.

The challenge is to get the AI to answer a question as accurately as possible, using the human definition of accuracy.

First, imagine an AI with some goal is going to answer a question, such as Q="What would happen if...?" The AI is under no compulsion to answer it honestly.

What would the AI do? Well, if it is sufficiently intelligent, it will model humans. It will use this model to understand what they meant by Q, and why they were asking. Then it will ponder various outcomes, and various answers it could give, and what the human understanding of those answers would be. This is what any sufficiently smart AI (friendly or not) would do.

Then the basic idea is to use modular design and corrigibility to extract the relevant pieces (possibly feeding them to another, differently motivated AI). What needs to be pieced together is: AI understanding of what human understanding of Q is, actual answer to Q (given this understanding), human understanding of various AI's answers (using model of human understanding), and minimum divergence between human understanding of answer and actual answer.

All these pieces are there, and if they can be safely extracted, the minimum divergence can be calculated and the actual answer calculated.

Models as definitions

6 Stuart_Armstrong 25 March 2015 05:46PM

A putative new idea for AI control; index here.

The insight this post comes from is a simple one: defining concepts such as “human” and “happy” is hard. A superintelligent AI will probably create good definitions of these, while attempting to achieve its goals: a good definition of “human” because it needs to control them, and of “happy” because it needs to converse convincingly with us. It is annoying that these definitions exist, but that we won’t have access to them.

 

Modelling and defining

Imagine a game of football (or, as you Americans should call it, football). And now imagine a computer game version of it. How would you say that the computer game version (which is nothing more than an algorithm) is also a game of football?

Well, you can start listing features that they have in common. They both involve two “teams” fielding eleven “players” each, that “kick” a “ball” that obeys certain equations, aiming to stay within the “field”, which has different “zones” with different properties, etc...

As you list more and more properties, you refine your model of football. There are some properties that distinguish real from simulated football (fine details about the human body, for instance), but most of the properties that people care about are the same in both games.

My idea is that once you have a sufficiently complex model of football that applies to both the real game and a (good) simulated version, you can use that as the definition of football. And compare it with other putative examples of football: maybe in some places people play on the street rather than on fields, or maybe there are more players, or maybe some other games simulate different aspects to different degrees. You could try and analyse this with information theoretic considerations (ie given two model of two different examples, how much information is needed to turn one into the other).

Now, this resembles the “suggestively labelled lisp tokens” approach to AI, or the Cyc approach of just listing lots of syntax stuff and their relationships. Certainly you can’t keep an AI safe by using such a model of football: if you try an contain the AI by saying “make sure that there is a ‘Football World Cup’ played every four years”, the AI will still optimise the universe and then play out something that technically fits the model every four years, without any humans around.

However, it seems to me that ‘technically fitting the model of football’ is essentially playing football. The model might include such things as a certain number of fouls expected; an uncertainty about the result; competitive elements among the players; etc... It seems that something that fits a good model of football would be something that we would recognise as football (possibly needing some translation software to interpret what was going on). Unlike the traditional approach which involves humans listing stuff they think is important and giving them suggestive names, this involves the AI establishing what is important to predict all the features of the game.

We might even combine such a model with the Turing test, by motivating the AI to produce a good enough model that it could a) have conversations with many aficionados about all features of the game, b) train a team to expect to win the world cup, and c) use it to program successful football computer game. Any model of football that allowed the AI to do this – or, better still, that a football-model module that, when plugged into another, ignorant AI, allowed that AI to do this – would be an excellent definition of the game.

It’s also one that could cross ontological crises, as you move from reality, to simulation, to possibly something else entirely, with a new physics: the essential features will still be there, as they are the essential features of the model. For instance, we can define football in Newtonian physics, but still expect that this would result in something recognisably ‘football’ in our world of relativity.

Notice that this approach deals with edge cases mainly by forbidding them. In our world, we might struggle on how to respond to a football player with weird artificial limbs; however, since this was never a feature in the model, the AI will simply classify that as “not football” (or “similar to, but not exactly football”), since the model’s performance starts to degrade in this novel situation. This is what helps it cross ontological crises: in a relativistic football game based on a Newtonian model, the ball would be forbidden from moving at speeds where the differences in the physics become noticeable, which is perfectly compatible with the game as its currently played.

 

Being human

Now we take the next step, and have the AI create a model of humans. All our thought processes, our emotions, our foibles, our reactions, our weaknesses, our expectations, the features of our social interactions, the statistical distribution of personality traits in our population, how we see ourselves and change ourselves. As a side effect, this model of humanity should include almost every human definition of human, simply because this is something that might come up in a human conversation that the model should be able to predict.

Then simply use this model as the definition of human for an AI’s motivation.

What could possibly go wrong?

I would recommend first having an AI motivated to define “human” in the best possible way, most useful for making accurate predictions, keeping the definition in a separate module. Then the AI is turned off safely and the module is plugged into another AI and used as part of its definition of human in its motivation. We may also use human guidance at several points in the process (either in making, testing, or using the module), especially on unusual edge cases. We might want to have humans correcting certain assumptions the AI makes in the model, up until the AI can use the model to predict what corrections humans would suggest. But that’s not the focus of this post.

There are several obvious ways this approach could fail, and several ways of making it safer. The main problem is if the predictive model fails to define human in a way that preserves value. This could happen if the model is too general (some simple statistical rules) or too specific (a detailed list of all currently existing humans, atom position specified).

This could be combated by making the first AI generate lots of different models, with many different requirements of specificity, complexity, and predictive accuracy. We might require some models make excellent local predictions (what is the human about to say?), others excellent global predictions (what is that human going to decide to do with their life?). 

Then everything defined as “human” in any of the models counts as human. This results in some wasted effort on things that are not human, but this is simply wasted resources, rather than a pathological outcome (the exception being if some of the models define humans in an actively pernicious way – negative value rather than zero – similarly to the false-friendly AIs’ preferences in this post).

The other problem is a potentially extreme conservatism. Modelling humans involves modelling all the humans in the world today, which is a very narrow space in the range of all potential humans. To prevent the AI lobotomising everyone to a simple model (after all, there does exist some lobotomised humans today), we would want the AI to maintain the range of cultures and mind-types that exist today, making things even more unchanging.

To combat that, we might try and identify certain specific features of society that the AI is allowed to change. Political beliefs, certain aspects of culture, beliefs, geographical location (including being on a planet), death rates etc... are all things we could plausibly identify (via sub-sub-modules, possibly) as things that are allowed to change. It might be safer to allow them to change in a particular range, rather than just changing altogether (removing all sadness might be a good thing, but there are many more ways this could go wrong, than if we eg just reduced the probability of sadness). 

Another option is to keep these modelled humans little changing, but allow them to define allowable changes themselves (“yes, that’s a transhuman, consider it also a moral agent.”). The risk there is that the modelled humans get hacked or seduced, and that the AI fools our limited brains with a “transhuman” that is one in appearance only.

We also have to beware of not sacrificing seldom used values. For instance, one could argue that current social and technological constraints mean that no one has today has anything approaching true freedom. We wouldn’t want the AI to allow us to improve technology and social structures, but never get more freedom than we have today, because it’s “not in the model”. Again, this is something we could look out for, if the AI has separate models of “freedom” we could assess and permit to change in certain directions.

Indifferent vs false-friendly AIs

9 Stuart_Armstrong 24 March 2015 12:13PM

A putative new idea for AI control; index here.

For anyone but an extreme total utilitarian, there is a great difference between AIs that would eliminate everyone as a side effect of focusing on their own goals (indifferent AIs) and AIs that would effectively eliminate everyone through a bad instantiation of human-friendly values (false-friendly AIs). Examples of indifferent AIs are things like paperclip maximisers, examples of false-friendly AIs are "keep humans safe" AIs who entomb everyone in bunkers, lobotomised and on medical drips.

The difference is apparent when you consider multiple AIs and negotiations between them. Imagine you have a large class of AIs, and that they are all indifferent (IAIs), except for one (which you can't identify) which is friendly (FAI). And you now let them negotiate a compromise between themselves. Then, for many possible compromises, we will end up with most of the universe getting optimised for whatever goals the AIs set themselves, while a small portion (maybe just a single galaxy's resources) would get dedicated to making human lives incredibly happy and meaningful.

But if there is a false-friendly AI (FFAI) in the mix, things can go very wrong. That is because those happy and meaningful lives are a net negative to the FFAI. These humans are running dangers - possibly physical, possibly psychological - that lobotomisation and bunkers (or their digital equivalents) could protect against. Unlike the IAIs, which would only complain about the loss of resources to the FAI, the FFAI finds the FAI's actions positively harmful (and possibly vice versa), making compromises much harder to reach.

And the compromises reached might be bad ones. For instance, what if the FAI and FFAI agree on "half-lobotomised humans" or something like that? You might ask why the FAI would agree to that, but there's a great difference to an AI that would be friendly on its own, and one that would choose only friendly compromises with a powerful other AI with human-relevant preferences.

Some designs of FFAIs might not lead to these bad outcomes - just like IAIs, they might be content to rule over a galaxy of lobotomised humans, while the FAI has its own galaxy off on its own, where its humans take all these dangers. But generally, FFAIs would not come about by someone designing a FFAI, let alone someone designing a FFAI that can safely trade with a FAI. Instead, they would be designing a FAI, and failing. And the closer that design got to being FAI, the more dangerous the failure could potentially be.

So, when designing an FAI, make sure to get it right. And, though you absolutely positively need to get it absolutely right, make sure that if you do fail, the failure results in a FFAI that can safely be compromised with, if someone else gets out a true FAI in time.

Superintelligence 28: Collaboration

7 KatjaGrace 24 March 2015 01:29AM

This is part of a weekly reading group on Nick Bostrom's book, Superintelligence. For more information about the group, and an index of posts so far see the announcement post. For the schedule of future topics, see MIRI's reading guide.


Welcome. This week we discuss the twenty-eighth section in the reading guide: Collaboration.

This post summarizes the section, and offers a few relevant notes, and ideas for further investigation. Some of my own thoughts and questions for discussion are in the comments.

There is no need to proceed in order through this post, or to look at everything. Feel free to jump straight to the discussion. Where applicable and I remember, page numbers indicate the rough part of the chapter that is most related (not necessarily that the chapter is being cited for the specific claim).

Reading: “Collaboration” from Chapter 14


Summary

  1. The degree of collaboration among those building AI might affect the outcome a lot. (p246)
  2. If multiple projects are close to developing AI, and the first will reap substantial benefits, there might be a 'race dynamic' where safety is sacrificed on all sides for a greater chance of winning. (247-8)
  3. Averting such a race  dynamic with collaboration should have these benefits:
    1. More safety
    2. Slower AI progress (allowing more considered responses)
    3. Less other damage from conflict over the race
    4. More sharing of ideas for safety
    5. More equitable outcomes (for a variety of reasons)
  4. Equitable outcomes are good for various moral and prudential reasons. They may also be easier to compromise over than expected, because humans have diminishing returns to resources. However in the future, their returns may be less diminishing (e.g. if resources can buy more time instead of entertainments one has no time for).
  5. Collaboration before a transition to an AI economy might affect how much collaboration there is afterwards. This might not be straightforward. For instance, if a singleton is the default outcome, then low collaboration before a transition might lead to a singleton (i.e. high collaboration) afterwards, and vice versa. (p252)
  6. An international collaborative AI project might deserve nearly infeasible levels of security, such as being almost completely isolated from the world. (p253)
  7. It is good to start collaboration early, to benefit from being ignorant about who will benefit more from it, but hard because the project is not yet recognized as important. Perhaps the appropriate collaboration at this point is to propound something like 'the common good principle'. (p253) 
  8. 'The common good principle': Superintelligence should be developed only for the benefit of all of humanity and in the service of widely shared ethical ideals. (p254)

Another view

Miles Brundage on the Collaboration section:

This is an important topic, and Bostrom says many things I agree with. A few places where I think the issues are less clear:

  • Many of Bostrom’s proposals depend on AI recalcitrance being low. For instance, a highly secretive international effort makes less sense if building AI is a long and incremental slog. Recalcitrance may well be low, but this isn’t obvious, and it is good to recognize this dependency and consider what proposals would be appropriate for other recalcitrance levels. 
  • Arms races are ubiquitous in our global capitalist economy, and AI is already in one. Arms races can stem from market competition by firms or state-driven national security-oriented R+D efforts as well as complex combinations of these, suggesting the need for further research on the relationship between AI development, national security, and global capitalist market dynamics. It's unclear how well the simple arms race model here matches the reality of the current AI arms race or future variations of it. The model's main value is probably in probing assumptions and inspiring the development of richer models, as it's probably too simple in to fit reality well as-is. For instance, it is unclear that safety and capability are close to orthogonal in practice today. If many AI people genuinely care about safety (which the quantity and quality of signatories to the FLI open letter suggests is plausible), or work on economically relevant near-term safety issues at each point is important, or consumers reward ethical companies with their purchases, then better AI firms might invest a lot in safety for self-interested as well as altruistic reasons. Also, if the AI field shifts to focus more on human-complementary intelligence that requires and benefits from long-term, high-frequency interaction with humans, then safety and capability may be synergistic rather than trading off against each other. Incentives related to research priorities should also be considered in a strategic analysis of AI governance (e.g. are AI researchers currently incentivized only to demonstrate capability advances in the papers they write, and could incentives be changed or the aims and scope of the field redefined so that more progress is made on safety issues?).
  • ‘AI’ is too course grained a unit for a strategic analysis of collaboration. The nature and urgency of collaboration depends on the details of what is being developed. An enormous variety of artificial intelligence research is possible and the goals of the field are underconstrained by nature (e.g. we can model systems based on approximations of rationality, or on humans, or animals, or something else entirely, based on curiosity, social impact, and other considerations that could be more explicitly evaluated), and are thus open to change in the future. We need to think more about differential technology development within the domain of AI. This too will affect the urgency and nature of cooperation.

Notes

1. In Bostrom's description of his model, it is a bit unclear how safety precautions affect performance. He says 'one can model each team's performance as a function of its capability (measuring its raw ability and luck) and a penalty term corresponding to the cost of its safety precautions' (p247), which sounds like they are purely a negative. However this wouldn't make sense: if safety precautions were just a cost, then regardless of competition, nobody would invest in safety. In reality, whoever wins control over the world benefits a lot from whatever safety precautions have been taken. If the world is destroyed in the process of an AI transition, they have lost everything! I think this is the model Bostrom means to refer to. While he says it may lead to minimum precautions, note that in many models it would merely lead to less safety than one would want. If you are spending nothing on safety, and thus going to take over a world that is worth nothing, you would often prefer to move to a lower probability of winning a more valuable world. Armstrong, Bostrom and Shulman discuss this kind of model in more depth.

2. If you are interested in the game theory of conflicts like this, The Strategy of Conflict is a great book. 

3. Given the gains to competitors cooperating to not destroy the world that they are trying to take over, research on how to arrange cooperation seems helpful for all sides. The situation is much like a tragedy of the commons, except for the winner-takes-all aspect: each person gains from neglecting safety, while exerting a small cost on everyone. Academia seems to be pretty interested in resolving tragedies of the commons, so perhaps that literature is worth trying to apply here.

4. The most famous arms race is arguably the nuclear one. I wonder to what extent this was a major arms race because nuclear weapons were destined to be an unusually massive jump in progress. If this was important, it leads to the question of whether we have reason to expect anything similar in AI.

In-depth investigations

If you are particularly interested in these topics, and want to do further research, these are a few plausible directions, some inspired by Luke Muehlhauser's list, which contains many suggestions related to parts of Superintelligence. These projects could be attempted at various levels of depth.

  1. Explore other models of competitive AI development.
  2. What policy interventions help in promoting collaboration?
  3. What kinds of situations produce arms races?
  4. Examine international collaboration on major innovative technology. How often does it happen? What blocks it from happening more? What are the necessary conditions? Examples: Concord jet, LHC, international space station, etc.
  5. Conduct a broad survey of past and current civilizational competence. In what ways, and under what conditions, do human civilizations show competence vs. incompetence? Which kinds of problems do they handle well or poorly? Similar in scope and ambition to, say, Perrow’s Normal Accidents and Sagan’s The Limits of Safety. The aim is to get some insight into the likelihood of our civilization handling various aspects of the superintelligence challenge well or poorly. Some initial steps were taken here and here.
  6. What happens when governments ban or restrict certain kinds of technological development? What happens when a certain kind of technological development is banned or restricted in one country but not in other countries where technological development sees heavy investment?
  7. What kinds of innovative technology projects do governments monitor, shut down, or nationalize? How likely are major governments to monitor, shut down, or nationalize serious AGI projects?
  8. How likely is it that AGI will be a surprise to most policy-makers and industry leaders? How much advance warning are they likely to have? Some notes on this here.
If you are interested in anything like this, you might want to mention it in the comments, and see whether other people have useful thoughts.

How to proceed

This has been a collection of notes on the chapter.  The most important part of the reading group though is discussion, which is in the comments section. I pose some questions for you there, and I invite you to add your own. Please remember that this group contains a variety of levels of expertise: if a line of discussion seems too basic or too incomprehensible, look around for one that suits you better!

Next week, we will talk about what to do in this 'crunch time'. To prepare, read Chapter 15. The discussion will go live at 6pm Pacific time next Monday 30 March. Sign up to be notified here.

Intelligence modules

4 Stuart_Armstrong 23 March 2015 04:24PM

A putative new idea for AI control; index here.

This idea, due to Eric Drexler, is to separate out the different parts of an AI into modules. There would be clearly designated pieces, either physical or algorithmic, with this part playing a specific role: this module would contain the motivation, this module the probability estimator, this module the models of the outside world, this module the natural language understanding unit, etc...

It's obvious how such a decomposition would be useful for many of the methods I've been detailing here. We could also distil each module - reduce it to a smaller, weaker (?) and more understandable submodule, in order to better understand what is going on. In one scenario, an opaque AI gets to design its successor, in the form of a series of such modules.

This property seems desirable; the question is, how could we get it?

EDIT: part of the idea of "modules" is that AIs often need to do calculations or estimations that would be of great value to us if we could access them in isolation. This idea is developed more in these posts.

 

Designing in modules

The main threat here is that a given submodule would contain more than just the properties we want. After all, a natural language parser could consist of a general intelligence plus a motivation to understand language. Another possible worry is that the modules are overfitted to the problem or to each other: the language parser works perfectly, but only in this one AI design.

There are several ways we could try and combat this.

  • Minimum length to the program (Eric's original main idea). The module must be as short as possible for its purpose.
  • If possible, start with a modularised AI, and track how the modules change as the AI's intelligence grows.
  • Have the AI extend the module to make it more transparent, without adding any extra functionality.
  • Check that the input-output map the AI presents (maybe require it so present it as a simple primitive recursive function with clear and simple "for" loops) is of commensurable complexity to the task at hand.
  • Add some noise to the situation: the new AI will not get exactly the same data as the old, the modules may get somewhat altered, and still have to work. Bugs will be introduced (this approach helps to combat the overfitting aspect of minimum length description).
  • Require that the module be "distant", according to some metric of modification to the module's program, from having other capabilities. For instance, a general intelligence motivated to understand language is easy to make into a model-making module, simply by changing the motivation; more narrow modules are probably more distant from each other.
  • Similarly, require that the performance of the modules becomes degraded if the world (or the world's descriptions) were substantially different, but not if they are the same information presented in a very different way.
  • General anti-overfitting methods, calibrated to not generate a push towards general abilities in the modules. This would require some skill and a lot of thought.
  • Focus on requiring statistical accuracy, rather than perfect performance.

If we allow false counterfactuals, then we can also:

  • Imagine that the modules would be connected up to other modules, made by (hypothetical) different AIs, with potentially different motivations.
  • Require that the modules not be useful as seeds for an AI of opposite motivation. For instance, an AI with opposite motivation would be allowed to flip a certain number of bits; if there was a general intelligence piece inside the module, then that would be something easier to co-opt, so dangerous to hand to an AI with opposite motivation. This is the "opposed" version of requiring modules to be "distant" from each other's capabilities.
  • In general, all the reduced impact/satisficing requirements push towards having modules that cannot become general intelligences.
  • The AI will dictate how to program these modules to a smart programmer, who will (counterfactually) not survive nor get to program the modules in the outside world.

Obviously anti-restriction-hacking would be useful to just module separation (and vice versa).

This is the beginning of the process of defining this, but it would be great to have a safe(ish) method of separating modules in this way.

Any suggestions?

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