ciphergoth comments on Problematic Problems for TDT - Less Wrong
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BTW, general question about decision theory. There appears to have been an academic study of decision theory for over a century, and causal and evidential decision theory were set out in 1981. Newcomb's paradox was set out in 1969. Yet it seems as though no-one thought to explore the space beyond these two decision theories until Eliezer proposed TDT, and it seems as if there is a 100% disconnect between the community exploring new theories (which is centered around LW) and the academic decision theory community. This seems really, really odd - what's going on?
This is simply not true. Robert Nozick (who introduced Newcomb's problem to philosophers) compared/contrasted EDT and CDT at least as far back as 1993. Even back then, he noted their inadequacy on several decision-theoretic problems and proposed some alternatives.
Me being ignorant of something seemed like a likely part of the explanation - thanks :) I take it you're referencing "The Nature of Rationality"? Not read that I'm afraid. If you can spare the time I'd be interested to know what he proposes -thanks!
I haven't read The Nature of Rationality in quite a long time, so I won't be of much help. For a very simple and short introduction to Nozick's work on decision theory, you should read this (PDF).
There were plenty of previous theories trying to go beyond CDT or EDT, they just weren't satisfactory.
This paper talks about reflexive decision models and claims to develop a form of CDT which one boxes.
It's in my to-read list but I haven't got to it yet so I'm not sure whether it's of interest but I'm posting it just in case (it could be a while until I have time to read it so I won't be able to post a more informed comment any time soon).
Though this theory post-dates TDT and so isn't interesting from that perspective.
Dispositional decision theory :P
... which I cannot find a link to the paper for, now. Hm. But basically it was just TDT, with less awareness of why.
EDIT: Ah, here it was. Credit to Tim Tyler.
I checked it. Not the same thing.
It should be noted that Newcomb's problem was considered interesting in Philosophy in 1969, but decision theories were studied more in other fields - so there's a disconnect between the sorts of people who usually study formal decision theories and that sort of problem.
(Deleting comments seems not to be working. Consider this a manual delete.)
Decision Theory is and can be applied to a variety of problems here. It's just that AI may face Newcomb-like problems and in particular we want to ensure a 1-boxing-like behavior on the part of AI.
The rationale for TDT-like decision theories is even more general, I think. There's no guarantee that our world contains only one copy of something. We want a decision theory that would let the AI cooperate with its copies or logical correlates, rather than wage pointless wars.
Constructing rigorous mathematical foundation of decision theory to explain what a decision problem or a decision or a goal are, is potentially more useful than resolving any given informally specified class of decision problems.
What is an example of such a real-world problem?
Negotiations with entities who can read the AI's source code.
Given the week+ delay in this response, it's probably not going to see much traffic, but I'm not convinced "reading" source code is all that helpful. Omega is posited to have nearly god-like abilities in this regard, but since this is a rationalist discussion, we probably have to rule out actual omnipotence.
If Omega intends to simply run the AI on spare hardware it has, then it has to be prepared to validate (in finite time and memory) that the AI hasn't so obfuscated its source as to be unintelligible to rational minds. It's also possible that the source to an AI is rather simple but it is dependent a large amount of input data in the form of a vast sea of numbers. I.e., the AI in question could be encoded as an ODE system integrator that's reliant on a massive array of parameters to get from one state to the next. I don't see why we should expect Omega to be better at picking out the relevant, predictive parts of these numbers than we are.
If the AI can hide things in its code or data, then it can hide functionality that tests to determine if it is being run by Omega or on its own protected hardware. In such a case it can lie to Omega just as easily as Omega can lie to the "simulated" version of the AI.
I think it's time we stopped positing an omniscient Omega in these complications to Newcomb's problem. They're like epicycles on Ptolemaic orbital theory in that they continue a dead end line of reasoning. It's better to recognize that Newcomb's problem is a red herring. Newcomb's problem doesn't demonstrate problems that we should expect AI's to solve in the real world. It doesn't tease out meaningful differences between decision theories.
That is, what decisions on real-world problems do we expect to be different between two AIs that come to different conclusions about Newcomb-like problems?
You should note that every problem you list is a special case. Obviously, there are ways of cheating at Newcomb's problem if you're aware of salient details beforehand. You could simply allow a piece of plutonium to decay, and do whatever the resulting Geiger counter noise tells you to. That does not, however, support your thesis that Newcomb's problem is a totally artificial problem with no logical intrusions into reality.
As a real-world example, imagine an off-the-shelf stock market optimizing AI. Not sapient, to make things simpler, but smart. When any given copy begins running, there are already hundreds or thousands of near-identical copies running elsewhere in the market. If it fails to predict their actions from its own, it will do objectively worse than it might otherwise do.
i don't see how your example is apt or salient. My thesis is that Newcomb-like problems are the wrong place to be testing decision theories because they do not represent realistic or relevant problems. We should focus on formalizing and implementing decision theories and throw real-world problems at them rather than testing them on arcane logic puzzles.
Well... no, actually. A good decision theory ought to be universal. It ought to be correct, and it ought to work. Newcomb's problem is important, not because it's ever likely to happen, but because it shows a case in which the normal, commonly accepted approach to decision theory (CDT) failed miserably. This 'arcane logic puzzle' is illustrative of a deeper underlying flaw in the model, which needs to be addressed. It's also a flaw that'd be much harder to pick out by throwing 'real world' problems at it over and over again.
Seems unlikely to work out to me. Humans evolved intelligence without Newcomb-like problems. As the only example of intelligence that we know of, it's clearly possible to develop intelligence without Newcomb-like problems. Furthermore, the general theory seems to be that AIs will start dumber than humans and iteratively improve until they're smarter. Given that, why are we so interested in problems like these (which humans don't universally agree about the answers to)?
I'd rather AIs be able to help us with problems like "what should we do about the economy?" or even "what should I have for dinner?" instead of worrying about what we should do in the face of something godlike.
Additionally, human minds aren't universal (assuming that universal means that they give the "right" solutions to all problems), so why should we expect AIs to be? We certainly shouldn't expect this if we plan on iteratively improving our AIs.