timtyler comments on Value is Fragile - Less Wrong

41 Post author: Eliezer_Yudkowsky 29 January 2009 08:46AM

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

Comments (88)

Sort By: Old

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

Comment author: Sniffnoy 28 March 2010 02:59:42PM *  1 point [-]

Tim, that's what the term means. This other thing that you have called a "utility function", is not in fact a utility function, because that's not what the term means. It's already been pointed out that not every list of preferences can be derived from a utility function. If you want to define or use a generalization of the notion of utility function, you should do so explicitly.

Comment author: timtyler 28 March 2010 05:06:54PM *  0 points [-]

I have no argument with the definition of the term "utility function". It is a function that maps outcomes to utilities - usually real numbers. The function I described did just that. If you don't understand that, then you should explain what aspects of the function's map from outcomes to utilities you don't understand - since it seemed to be a pretty simple one to me.

I don't think that all preferences can be expressed as a utility function. For example, some preferences are uncomputable.

Note that Tyrrell_McAllister2's reply makes exactly the same point as I am making.

Comment author: Sniffnoy 28 March 2010 05:36:46PM 1 point [-]

See, this would have been a lot clearer if you had specified initially that your objection was to the domain.

Comment author: timtyler 28 March 2010 06:54:53PM *  1 point [-]

Sorry if there was any confusion. Here are all the possible outcomes - and their associated (real valued) utilities - laboriously spelled out in a table:

Remembers being presented with (A,B) and chooses A - utility 1.0.

Remembers being presented with (A,B) and chooses B - utility 0.0.

Remembers being presented with (B,C) and chooses B - utility 1.0.

Remembers being presented with (B,C) and chooses C - utility 0.0.

Remembers being presented with (C,A) and chooses C - utility 1.0.

Remembers being presented with (C,A) and chooses A - utility 0.0.

Other action - utility 0.0.