[EM] 3P methods. 3P Criterion.

[MIKE OSSIPOFF]

I've mentioned that I like that Bucklin gives 3 protection levels (to be defined later in this post). There are other methods
that give that too, along with passing FBC.

Because there are a number of methods giving those 3 protection levels, I'd like to give them a name.

I'll call them 3P methods. They meet the 3P Criterion.

Definition:

A method is 3P, and meets the 3P Criterion if, with that method, there are three "protection-levels" (referred to
here as "top", "middle", and "bottom"), such that each voter can "protect" any set of candidates at top, and
can simultaneously protect any other set of candidates at middle.

To protect a set of candidates at a particular protection level means to vote in such a way that, if a majority
voted in that way, no candidate whom that majority didn't protect at that level or higher can't win.

[end of definition of 3P methods and 3P criterion]

A method is a 3PD method, and meets the 3PD criterion, if it allows a voter to discriminate among candidates
whom s/he protects at at least one of the upper 2 protection-levels.

[end of definition of 3PD methods and the 3PD criterion]


Some methods meeting 3P:

Bucklin, MDDA, MAMPO, DP (proposed by Chris Benham, defined later), MCA, 

Some methods meeting 3PD:

Bucklin, MDDA, MAMPO

3PD methods can be compared according to in what way the method allows the voter to discriminate
among candidates s/he protects at some non-bottom protection level. I haven't looked at that.

I don't know if MMPO meets FBC, but it fails 3P, and I (for the 2nd time) abandon MMPO.

I'm still visiting, and I promised my girlfriend that I'd only post this quick note, and that I would not
look at the mailing list or my inbox right now. I might get a chance to get back to the computer
later today. If not, then tomorrow for sure.

Mike Ossipoff



 		 	   		  
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