Bart's "Median Rating" method?
DEMOREP1 at aol.com
DEMOREP1 at aol.com
Wed May 19 18:39:11 PDT 1999
Mr. Eppley wrote--
I think the definition of Bart's Median rating method needs
clarification, since Bart's claim about highest median rating
and majority appears dubious. Here's an example to illustrate
the problem:
voter 1: A=95, B=65
voter 2: A=85, B=60
voter 3: A=50, B=20
voter 4: A=40, B= 0
voter 5: A=45, B=55
There is a majority (80%) who rank A ahead of B.
Average rating for A = 63
Average rating for B = 40
Median rating for A = 50?
Median rating for B = 55?
If I've interpreted correctly how Bart intends it to be
tallied, B is the candidate with the highest "median rating."
But I wouldn't agree that B is rated higher than A by a
majority of voters.
----
D- This is deja vu all over again from late 1998.
I suggested that if medians are to be used, then (1) only the choices getting
above 50 medians (on a 0 to 100 scale) should (2) go head to head (Condorcet)
(with (3) the highest median winning if there was no Condorcet winner).
Median = middle value of all values ranked high to low
A 65, 60, 55, 20, 0 median 55
B 95, 85, 50, 45, 40 median 50
Thus, B automatically wins (median 55) since A does not have an above 50
median (i.e. stop at step (1)).
If voter 3 voted A=51, B=20, then the A median would be 51 so that A should
beat B head to head (i.e. stop at step (2)).
The above 50 median test is a refinement of my suggested YES/ NO test (i.e.
it gives some more info about the intensity of the support for a choice).
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