[EM] Re: EM] There's nothing wrong with Average Rating.

[wclark at xoom.org]

> It was my understanding that Arrow's theorum does apply to CR.  Actually
> it applies to Approval as well, it's just that Approval meets all of the
> conditions except allowing voters to rank three or more choices in
> order.

It was my understanding that Arrow's theorem only applies to ordinal
methods, and not to cardinal methods.  At least, I've never seen a proof
that didn't require ordinal-only ranking.

I believe Arrow's own formulation was restricted to dealing only with
social choice functions over preference *orderings*, without any reference
to the intensity of preference (i.e. cardinality.)  It's been a while
since I actually looked at his (1951) though.

I'm sure somebody else on the list will know for certain what the facts
are here... I'll start digging through the archives to see if this has
come up before.

-Bill

-- 
Ralph Nader for US President in 2004
http://votenader.org/