AlexMennen comments on How Much Evidence Does It Take? - Less Wrong

34 Post author: Eliezer_Yudkowsky 24 September 2007 04:06AM

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

Comments (29)

Sort By: Old

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

Comment author: Perplexed 23 March 2011 04:28:23AM 2 points [-]

Clearly you understand me now, and I think that I understand you.

A "bit of evidence" does not unambiguously tell someone whether you mean probability-bit or odds-ratio-bit, and Eliezer does not distinguish between them properly.

OK, if what is at issue here is whether Eliezer was sufficiently clear, then I'll bow out. Obviously, he was not sufficiently clear from your viewpoint. I will say, though, that your comment is the first time I have seen the word "evidence" used by a Bayesian for anything other than a log odds ratio.

Log odds evidence has the virtue that it is additive (when independent). On the other hand, your idea of a log probability meaning of 'evidence' has the virtue that a question can be decided by a finite amount of evidence.

Comment author: AlexMennen 23 March 2011 04:39:30AM 3 points [-]

I will say, though, that your comment is the first time I have seen the word "evidence" used by a Bayesian for anything other than a log odds ratio.

Eliezer used it to mean log probability in the section that I quoted. That was what I was complaining about.

Comment author: Perplexed 23 March 2011 04:55:04AM 0 points [-]

Ok, I think you are misinterpreting, but I see what you mean. When EY writes:

...I have transmitted three bits of information to you, because I informed you of an outcome whose probability was 1/8.

I take this as illustrating the definition of bits in general, rather than bits of 'evidence'. But, yes, I agree with you now that placing that explanation in a paragraph with that lead sentence promising a definition of 'evidence' - well it definitely could have been written more clearly.