[EM] Re: "weak & strong preferences", Steve Eppley EM post , 5 Mar.1997

[James Green-Armytage]

Chris quoted Steve Eppley's post at:
http://lists.electorama.com/pipermail/election-methods-electorama.com/1997-March/001392.html


Hi Chris,

	Thank you for the reference! That basically looks like the same idea,
with only subtle differences. I agree that S/WPO strikes a pretty good
balance between strategic resistance and simplicity of explanation, hence
it might not be a bad choice for a first-wave Condorcet method.
	Here's the main (minor, but worth noting) difference I see between
Steve's original proposal and my current understanding of S/WPO... Steve's
method counts > initially as >, and then changes it to = if there is no
CW. Thus, the direction of the pairwise defeats could change in the second
count. My version of S/WPO, on the other hand, counts > as > when it comes
to the direction of the defeat (whether there is a CW or not), but counts
it as = for the purpose of finding the strength of the defeats. Thus the
initial defeat directions are preserved. I think that the latter approach
is preferable, in that it has greater continuity than the first.
	(Note that my version of AERLO/ATLO differs from Mike Ossipoff's
definition in a similar way.)

my best,
James Green-Armytage