= 27d567bc2d48d9f40e9ccc20ea370b15)
twanvl comments on Decision Theories: A Less Wrong Primer - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (172)
Ahh, I guess we are talking about same thing. My point is that given more information - and making more conclusions - EDT should smoke. The CDT gets around requirement for more information by cheating - we wrote some of that information implicitly into CDT - we thought CDT is a good idea because we know our world is causal. Whenever EDT can reason that CDT will work better - based on evidence in support of causality, the model of how lesions work, et cetera - the EDT will act like CDT. And whenever CDT reasons that EDT will work better - the CDT self modifies to be EDT, except that CDT can't do it on spot and has to do it in advance. The advanced decision theories try to 'hardcode' more of our conclusions about the world into the decision theory. This is very silly.
If you test humans, I think it is pretty clear that humans work like EDT + evidence for causality. Take away evidence for causality, and people can believe that deciding to smoke retroactively introduces the lesion.
edit: ahh, wait, the EDT is some pretty naive theory that can not even process anything as complicated as evidence for causality working in our universe. Whatever then, a thoughtless approach leads to thoughtless results, end of story. The correct decision theory should be able to control for pre-existing lesion when it makes sense to do so.
Can you explain this?
EDT is described as $V(A) = \sum_{j} P(O_j | A) U(O_j)$. If you have knowledge about the mechanisms behind the how the lesion causes smoking, that would change $P(A | O_j)$ and therefore also $P(O_j | A)$.
I don't see how knowledge how the lesion works would affect the probabilities when you don't know if you have lesion and the probability of having lesion.
Also:
You would still have priors for all of these things.
Even if you do, how is knowing that the lesion causes cancer going to change anything about P(smokes|gets cancer) ? The issue is that you need to do two equations, one for case when you do have lesion, and other for when you don't have lesion. The EDT just confuses those together.
The lesion could work in (at least) two ways:
In case 1, you should follow EDT, and use a decision theory that will make you not decide to smoke. In case 2, you know that the lesion doesn't apply to you, so go ahead and smoke. In case 3, conditioned on your utility function (which you know), the probability of the lesion no longer depends on your decision. So, you can smoke.