[EM] Re: AWP versus DMC

Araucaria Araucana araucaria.araucana at gmail.com
Thu Sep 8 08:40:49 PDT 2005

James Green-Armytage <jarmyta <at> antioch-college.edu> writes:
> 	What is the simplest explanation of DMC?

1. Drop any candidate defeated by any other higher-approved candidate.
   We call any dropped candidates /definitively defeated/.  
   Call the remaining candidates the Provisional Set (or P-set).
2. Drop candidates defeated by lower-approved members of the P-set.
3. There is one winner, the /definitive majority/ winner. 

> The AWP explanation above is not as simple as approval, MMPO, IRV, etc.,
> but not staggeringly complex.

I agree to some extent.  If DMC is adopted, I'm in favor of tabulating the
approval-pairwise (or cardinal pairwise) array in addition to the pairwise
array+ approval scores.  Then at some future time, voters can decide if the
slight additional complexity is worthwhile.  At the very least, the
information would be available.

By the way, I've thought of a fairly simple way to add ratings to an ordinal

Voters rank the candidate 1st, 2nd, 3rd, etc., but can then give a rating of 0
to 100 to each rank, using the following method:

1) The default rating of rank 1 is 100.
2) For lower ranks with candidates, the default rating is the same as that of
   the next higher rank.
3) Unranked candidates (or ranks with without candidates) are rated 0.

This way, a relatively simple ballot could simply rank 1st, 2nd and 3rd
choices (with equal rank allowed) and by default they would each receive a
rating of 100.

But if someone wants to enter a 4th choice with rating of, say, 70, they
simply rank X as 4th and set 4th's rating to 70.  1st, 2nd and 3rd still have
their default ratings of 100.

As stated previously by Adam Tarr, DMC extends to ratings quite easily.  DMC
should generally be considered in tandem with the Pairwise [Bubble] Sorted
methods -- starting with a seed rank using some measure (approval, ratings,
borda), pairwise sorting gives the complete ranking, while DMC (as
above) finds the winner directly.  See the electowiki page for more



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