Dmytry comments on Decision Theories: A Less Wrong Primer - Less Wrong

69 Post author: orthonormal 13 March 2012 11:31PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Article Navigation

Comments (172)
Tags: adt udt introduction timeless cdt newcomb tdt newcombs_problem prisoners_dilemma decision_theory

Comments (172)

You are viewing a single comment's thread. Show more comments above.

Comment author: twanvl 15 March 2012 11:16:56AM *  0 points [-]

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.

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 $P(O_j | A)$.

Comment author: Dmytry 15 March 2012 11:24:44AM *  0 points [-]

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.

Comment author: twanvl 15 March 2012 11:55:21AM 0 points [-]

Also:

when you don't know if you have lesion and the probability of having lesion.

You would still have priors for all of these things.

Comment author: Dmytry 15 March 2012 12:07:15PM *  0 points [-]

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.

Comment author: twanvl 15 March 2012 11:30:33AM 0 points [-]

The lesion could work in (at least) two ways:

  1. it makes you more likely to use a decision theory that leads you to decide to smoke
  2. it only makes irrational people more likely to smoke.
  3. it changes people's utility of smoking.

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.

Powered by Reddit Powered by Reddit