[EM] Dyadic approval implemented as CR

Richard Moore rmoore4 at home.com
Thu Aug 23 21:01:50 PDT 2001

Roy wrote:
> How about a CR ballot that is scored as Dyadic approval? Votes in the 
> top half of the ratings scale score 1 point (in a pairwise matrix) 
> over those in the bottom half. Within a half, those in the upper half-
> of-the-half score a half point over those in the lower. And so forth. 
> Sum the matrices, run a Condorcet method.

Part of the appeal of the dyadic ballots is that they offer 
more expressivity than mere rank voting. So you can not only 
say that you like B better than C (B>C), you can say you 
like B much, much better than C (B>>>C). But this binary 
scoring method loses that advantage. In fact, if we use 
summation, and I assume you mean "sum the rows", it's an 
approximation to Borda (with a power-of-two number of 
candidates it *is* Borda, if we ignore tied rankings) so I 
would think it has Borda's strategy problems. If we use a 
Condorcet method instead, it seems like we haven't gained 
anything over the Condorcet method with ordinary ranked 
ballots. Am I missing something?


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