EHeller comments on Conceptual Analysis and Moral Theory - Less Wrong

60 Post author: lukeprog 16 May 2011 06:28AM

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Comment author: nshepperd 21 November 2014 02:29:29AM *  3 points [-]

Choosing is deliberation, deliberation is choosing. Just consider the alternatives (one-box, two-box) and do the one that results in you having more money.

Whichever choice you decide to make is the choice you were always going to make

The keyword here is decide. Just because you were always going to make that choice doesn't mean you didn't decide. You weighed up the costs and benefits of each option, didn't you?

It really isn't hard. Just think about it, then take one box.

Comment author: EHeller 21 November 2014 02:44:42AM -1 points [-]

Choosing is deliberation, deliberation is choosing. Just consider the alternatives (one-box, two-box) and do the one that results in you having more money.

Clearly thats two boxing. Omega already made his choice, so if he thought I'd two box, I'll get;

-One box: nothing -two boxing: the small reward

if Omega thought I'd one box: -One box:big reward -two box: big reward + small reward

Two boxing results in more money no matter how Omega thought I'd chose.

Comment author: nshepperd 21 November 2014 03:02:40AM 3 points [-]

Missing the Point: now a major motion picture.

Comment author: Lumifer 21 November 2014 02:47:24AM *  2 points [-]

Is that the drumbeat of nshepperd's head against the desk that I hear..? :-D

Comment author: Jiro 21 November 2014 04:02:10PM 0 points [-]

What if I try to predict what Omega does, and do the opposite?

That would mean that either 1) there are some strategies I am incapable of executing, or 2) Omega can't in principle predict what I do, since it is indirectly predicting itself.

Alternatively, what if instead of me trying to predict Omega, we run this with transparent boxes and I base my decision on what I see in the boxes, doing the opposite of what Omega predicted? Again, Omega is indirectly predicting itself.

Comment author: nshepperd 22 November 2014 01:53:30AM *  1 point [-]

I don't see how this is relevant, but yes, in principle it's impossible to predict the universe perfectly. On account of the universe + your brain is bigger than your brain. Although, if you live in a bubble universe that is bigger than the rest of the universe, whose interaction with the rest of the universe is limited precisely to your chosen manipulation of the connecting bridge; basically, if you are AIXI, then you may be able to perfectly predict the universe conditional on your actions.

This has pretty much no impact on actual newcomb's though, since we can just define such problems away by making omega do the obvious thing to prevent such shenanigans ("trolls get no money"). For the purpose of the thought experiment, action-conditional predictions are fine.

IOW, this is not a problem with Newcomb's. By the way, this has been discussed previously.

Comment author: EHeller 22 November 2014 02:29:05AM 0 points [-]

You've now destroyed the usefulness of Newcomb as a potentially interesting analogy to the real world. In real world games, my opponent is trying to infer my strategy and I'm trying to infer theirs.

If Newcomb is only about a weird world where omega can try and predict the player's actions, but the player is not allowed to predict omega's, then its sort of a silly problem. Its lost most of its generality because you've explicitly disallowed the majority of strategies.

If you allow the player to pursue his own strategy, then its still a silly problem, because the question ends up being inconsistent (because if omega plays omega, nothing can happen).

Comment author: nshepperd 22 November 2014 02:59:43AM *  0 points [-]

In real world games, we spend most our time trying to make action-conditional predictions. "If I play Foo, then my opponent will play Bar". There's no attempting to circularly predict yourself with unconditional predictions. The sensible formulation of Newcomb's matches that.

(For example, transparent boxes: Omega predicts "if I fill both boxes, then player will _" and fills the boxes based on that prediction. Or a few other variations on that.)

Comment author: EHeller 22 November 2014 04:17:13AM *  0 points [-]

In many (probably most?) games we consider the opponents strategy, not simply their next move. Making moves in an attempt to confuse your opponent's estimation of your own strategy is a common tactic in many games.

Your "modified Newcomb" doesn't allow the chooser to have a strategy- they aren't allowed to say "if I predict Omega did X, I'll do Y." Its a weird sort of game where my opponent takes my strategy into account, but something keeps me from considering my opponents.

Comment author: hairyfigment 21 November 2014 07:32:10PM 1 point [-]

Can't Omega follow the strategy of 'Trolls get no money,' which by assumption is worse for you? I feel like this would result in some false positives, but perhaps not - and the scenario says nothing about the people who don't get to play in any case.

Comment author: Jiro 21 November 2014 08:48:53PM *  1 point [-]

Can't Omega follow the strategy of 'Trolls get no money,

No, because that's fighting the hypothetical. Assume that he doesn't do that.

Comment author: wedrifid 22 November 2014 03:41:18AM 4 points [-]

No, because that's fighting the hypothetical. Assume that he doesn't do that.

It is actually approximately the opposite of fighting the hypothetical. It is managing the people who are trying to fight the hypothetical. Precise wording of the details of the specification can be used to preempt such replies but for casual defininitions that assume good faith sometimes explicit clauses for the distracting edge cases need to be added.

Comment author: Jiro 23 November 2014 03:43:48AM *  1 point [-]

It is fighting the hypothetical because you are not the only one providing hypotheticals. I am too; I'm providing a hypothetical where the player's strategy makes this the least convenient possible world for people who claim that having such an Omega is a self-consistent concept. Saying "no, you can't use that strategy" is fighting the hypothetical.

Moreover, the strategy "pick the opposite of what I predict Omega does" is a member of a class of strategies that have the same problem; it's just an example of such a strategy that is particularly clear-cut, and the fact that it is clear-cut and blatantly demonstrates the problem with the scenario is the very aspect that leads you to call it trolling Omega. "You can't troll Omega" becomes equivalent to "you can't pick a strategy that makes the flaw in the scenario too obvious".

Comment author: nshepperd 23 November 2014 12:10:31PM *  2 points [-]

If your goal is to show that Omega is "impossible" or "inconsistent", then having Omega adopt the strategy "leave both boxes empty for people who try to predict me / do any other funny stuff" is a perfectly legitimate counterargument. It shows that Omega is in fact consistent if he adopts such strategy. You have no right to just ignore that counterargument.

Indeed, Omega requires a strategy for when he finds that you are too hard to predict. The only reason such a strategy is not provided beforehand in the default problem description is because we are not (in the context of developing decision theory) talking about situations where you are powerful enough to predict Omega, so such a specification would be redundant. The assumption, for the purpose of illuminating problems with classical decision theory, is that Omega has vastly more computational resources than you do, so that the difficult decision tree that presents the problem will obtain.

By the way, it is extremely normal for there to be strategies you are "incapable of executing". For example, I am currently unable to execute the strategy "predict what you will say next, and counter it first", because I can't predict you. Computation is a resource like any other.

Comment author: Jiro 23 November 2014 04:50:26PM 1 point [-]

If your goal is to show that Omega is "impossible" or "inconsistent", then having Omega adopt the strategy "leave both boxes empty for people who try to predict me / do any other funny stuff" is a perfectly legitimate counterargument.

If you are suggesting that Omega read my mind and think "does this human intend to outsmart me, Omega", then sure he can do that. But that only takes care of the specific version of the strategy where the player has conscious intent.

If you're suggesting "Omega figures out whether my strategy is functionally equivalent to trying to outsmart me", you're basically claiming that Omega can solve the halting problem by analyzing the situation to determine if it's an instance of the halting problem, and outputting an appropriate answer if that is the case. That doesn't work.

Indeed, Omega requires a strategy for when he finds that you are too hard to predict.

That still requires that he determine that I am too hard to predict, which either means solving the halting problem or running on a timer. Running on a timer is a legitimate answer, except again it means that there are some strategies I cannot execute.

The assumption, for the purpose of illuminating problems with classical decision theory, is that Omega has vastly more computational resources than you do, so that the difficult decision tree that presents the problem will obtain.

I thought the assumption is that I am a perfect reasoner and can execute any strategy.

Comment author: nshepperd 23 November 2014 10:33:22PM *  1 point [-]

Running on a timer is a legitimate answer

There's your answer.

except again it means that there are some strategies I cannot execute.

I don't see how omega running his simulation on a timer makes any difference for this, but either way this is normal and expected. Problem resolved.

I thought the assumption is that I am a perfect reasoner and can execute any strategy.

Not at all. Though it may be convenient to postulate arbitrarily large computing power (as long as Omega's power is increased to match) so that we can consider brute force algorithms instead of having to also worry about how to make it efficient.

(Actually, if you look at the decision tree for Newcomb's, the intended options for your strategy are clearly supposed to be "unconditionally one-box" and "unconditionally two-box", with potentially a mixed strategy allowed. Which is why you are provided wth no information whatsoever that would allow you to predict omega. And indeed the decision tree explicitly states that your state of knowledge is identical whether omega fills or doesn't fill the box.)

Comment author: dxu 23 November 2014 09:13:32PM 1 point [-]

I thought the assumption is that I am a perfect reasoner and can execute any strategy.

Why would this be the assumption?

Comment author: EHeller 24 November 2014 01:43:35AM *  0 points [-]

If your goal is to show that Omega is "impossible" or "inconsistent", then having Omega adopt the strategy "leave both boxes empty for people who try to predict me / do any other funny stuff" is a perfectly legitimate counterargument. It shows that Omega is in fact consistent if he adopts such strategy. You have no right to just ignore that counterargument.

This contradicts the accuracy stated at the beginning. Omega can't leave both boxes empty for people who try to adopt a mixed strategy AND also maintain his 99.whatever accuracy on one-boxers.

And even if Omega has way more computational than I do, I can still generate a random number. I can flip a coin thats 60/40 one-box, two-box. The most accurate Omega can be, then, is to assume I one box.

Comment author: nshepperd 24 November 2014 03:10:56AM 2 points [-]

This contradicts the accuracy stated at the beginning. Omega can't leave both boxes empty for people who try to adopt a mixed strategy AND also maintain his 99.whatever accuracy on one-boxers.

He can maintain his 99% accuracy on deterministic one-boxers, which is all that matters for the hypothetical.

Alternatively, if we want to explicitly include mixed strategies as an available option, the general answer is that Omega fills the box with probability = the probability that your mixed strategy one-boxes.

Comment author: dxu 23 November 2014 04:30:14PM *  0 points [-]

All of this is very true, and I agree with it wholeheartedly. However, I think Jiro's second scenario is more interesting, because then predicting Omega is not needed; you can see what Omega's prediction was just by looking in (the now transparent) Box B.

As I argued in this comment, however, the scenario as it currently is is not well-specified; we need some idea of what sort of rule Omega is using to fill the boxes based on his prediction. I have not yet come up with a rule that would allow Omega to be consistent in such a scenario, though, and I'm not sure if consistency in this situation would even be possible for Omega. Any comments?

Comment author: wedrifid 24 November 2014 01:54:18AM *  2 points [-]

As I argued in this comment, however, the scenario as it currently is is not well-specified; we need some idea of what sort of rule Omega is using to fill the boxes based on his prediction.

Previous discussions of Transparent Newcomb's problem have been well specified. I seem to recall doing so in footnotes so as to avoid distraction.

I have not yet come up with a rule that would allow Omega to be consistent in such a scenario, though, and I'm not sure if consistency in this situation would even be possible for Omega. Any comments?

The problem (such as it is) is that there is ambiguity between the possible coherent specifications, not a complete lack. As your comment points out there are (merely) two possible situations for the player to be in and Omega is able to counter-factually predict the response to either of them, with said responses limited to a boolean. That's not a lot of permutations. You could specify all 4 exhaustively if you are lazy.

IF (Two box when empty AND One box when full) THEN X
IF ...

Any difficulty here is in choosing the set of rewards that most usefully illustrate the interesting aspects of the problem.

Comment author: wedrifid 24 November 2014 01:03:37AM *  1 point [-]

I am too; I'm providing a hypothetical where the player's strategy makes this the least convenient possible world for people who claim that having such an Omega is a self-consistent concept.

It may be the least convenient possible world. More specifically it is the minor inconvenience of being careful to specify the problem correctly so as not to be distracted. Nshepperd gives some of the reason typically used in such cases.

Moreover, the strategy "pick the opposite of what I predict Omega does" is a member of a class of strategies that have the same problem

What happens when you try to pick the the opposite of what you predict Omega does is something like what happens when you try to beat Deep Fritz 14 at chess while outrunning a sports car. You just fail. Your brain is a few of pounds of fat approximately optimised for out-competing other primates for mating opportunities. Omega is a super-intelligence. The assumption that Omega is smarter than the player isn't an unreasonable one and is fundamental to the problem. Defying it is a particularly futile attempt to fight the hypothetical by basically ignoring it.

Generalising your proposed class to executing maximally inconvenient behaviours in response to, for example, the transparent Newcomb's problem is where it gets actually gets (tangentially) interesting. In that case you can be inconvenient without out-predicting the superintelligence and so the transparent Newcomb's problem requires more care with the if clause.

Comment author: dxu 21 November 2014 08:56:22PM *  0 points [-]

In the first scenario, I doubt you would be able to predict Omega with sufficient accuracy to be able to do what you're suggesting. Transparent boxes, though, are interesting. The problem is, the original Newcomb's Problem had a single situation with two possible choices involved; tranparent Newcomb, however, involves two situations:

  1. Transparent Box B contains $1000000.
  2. Transparent Box B contains nothing.

It's unclear from this what Omega is even trying to predict; is he predicting your response to the first situation? The second one? Both? Is he following the rule: "If the player two-boxes in either situation, fill Box B with nothing"? Is he following the rule: "If the player one-boxes in either situation, fill Box B with $1000000"? The problem isn't well-specified; you'll have to give a better description of the situation before a response can be given.

Comment author: Jiro 21 November 2014 10:16:48PM *  0 points [-]

In the first scenario, I doubt you would be able to predict Omega with sufficient accuracy to be able to do what you're suggesting.

That falls under 1) there are some strategies I am incapable of executing.

tranparent Newcomb, however, involves two situations: 1. Transparent Box B contains $1000000. 2. Transparent Box B contains nothing.

The transparent scenario is just a restatement of the opaque scenario with transparent boxes instead of "I predict what Omega does". If you think the transparent scenario involves two situations, then the opaque scenario involves two situations as well. (1=opaque box B contains $1000000, and I predict that Omega put in $1000000 and 2=opaque box B contains nothing, and I predict that Omega puts in nothing.) If you object that we have no reason to think both of those opaque situations are possible, I can make a similar objection to the transparent situations.