[EM] Ratings as a standard

[Blake Cretney]

Bart Ingles wrote:

> Nearly a year ago, Blake objected to my use of average ratings as a
> standard for comparing methods, partly on the grounds that average (or
> total) ratings would give more weight to extremist voters.
> 
> The discussion assumed we were using sincere ratings in hypothetical
> examples only, and that the ratings were on an absolute scale.  There
> was no suggestion that the ratings standard itself be used as a voting
> method.
> 
> At the time I had suggested some ideas for ratings-based standards where
> the effect of extreme votes could be limited.  It now occurs to me that
> this is entirely unnecessary, and that extremist voting is not a
> problem.
> 
> All you need to do is stipulate that comparisons using average ratings
> (i.e. social utilities) are valid so long as the actual methods you are
> comparing don't give undue influence to extremist voters.  You simply
> compare the methods with the understanding that no method would or
> should yield the highest possible rating in all situations.

My problem with this, is that I do not accept the average ratings
standard.  Since it is fairly intuitive, I felt I should give some
justification for why I reject it.  The best reason for rejecting a
standard, it seems to me, is if it can be shown to require an absurd
conclusion, in some cases.

The average ratings standard seems to do this, for examples like the
following:
1  voter   A 500 B 0
40 voters  A 5   B 9
The average ratings standard says that A should win, but I tend to
doubt this.  It seems more reasonable to conclude that the single
voter is being unreasonable.

Of course, you could avoid this conclusion by coming up with a new
standard that balanced average ratings with some kind of extremist
avoidance.  But such a standard would no longer be intuitive, and
there would be no real reason for accepting it.  Such a standard might
restrict average ratings from falling into obvious absurdity, but I
would suspect that its conclusions would still be incorrect, just not
taken to the logical extreme.

---
Blake Cretney