[EM] ASCII maps

[Kevin Venzke]

Hi Kristofer,

--- En date de : Ven 25.2.11, Kristofer Munsterhjelm <km-elmet at broadpark.no> a écrit :
> FWIW, I dug up that old code and made a map of my own using
> Kendall tau distance between the different methods' output
> orderings. The ballot generator was a combination of IIC
> (every ordering equally likely) and a spatial model - every
> other round used the one, every other the other.
> 
> The picture is here: http://munsterhjelm.no/km/elections/Methods.png
> 
> I don't see any obvious axial characteristics. Perhaps
> methods closer to the bottom are more indecisive, but it
> ranks Copeland in the "misc Condorcet methods" blob, ahead
> of VMedian-Ratings which does try to break ties quite a bit
> more. Or perhaps methods closer to the bottom make use of
> less information at once, which could explain why the
> eigenvector-type methods are near the top.

That's an interesting picture. I don't really understand the proximities
at all. I can see FPP near Antiplurality. And not too far away is Random
Pair. IFPP is near Plurality as expected, but totally opposite IRV. Were
there tons of candidates I wonder? I'm inclined to guess that Maximin(wv)
and the three Gradual methods at the bottom give very strange results.

I wonder if you ever tried it with some subsets of methods to see if
you got different orientation. Or if having fewer points perhaps makes it
easier to find a good map. For example the map I showed you with the huge
Borda cloud showed a few of the main methods relocated in relation to each
other. I currently think it was based on nothing, because I can plot the
main 6 methods on notebook paper and the arrangement and distances make
total sense. Doesn't appear that anything is being fudged.

(On the other hand, Borda as I had it definitely doesn't satisfy 
Plurality, and such methods don't fit the north-south test well...)

Kevin