[EM] strength vs. length: Short Ranked Pairs (SRP)

2004-11-16 Thread Jobst Heitzig
Some correction: I defined SRP as follows: Definition: SHORT RANKED PAIRS (SRP) Affirm the lexicographically maximal *short* acyclic subset of all defeats. Def.: SHORT ACYCLIC SET OF DEFEATS -- An acyclic set of defeats

Re: [EM] IRV in San Francisco

2004-11-16 Thread Eric Gorr
At 8:03 PM -0800 11/15/04, Bart Ingles wrote: What would be an example of a spoiler (ICC or other violation) which is NOT an irrelevant alternative? With IIA, the spoiler is a candidate that is either added or removed from the ballots. With ICC, the spoiler is among the ballots already.

RE: [EM] IRV in San Francisco

2004-11-16 Thread Paul Kislanko
This is an incredibly confusing statement. No one can be added or removed from a ballot after the votes have been counted, so by this distinction there is no such thing as an IIA spoiler. More precisely, the adding and removing of an alternative is an alytical trick that helps prove attributes of

RE: [EM] IRV in San Francisco

2004-11-16 Thread Eric Gorr
At 3:14 PM -0600 11/16/04, Paul Kislanko wrote: No one can be added or removed from a ballot after the votes have been counted, Sure one can...just do it and recalculate. so by this distinction there is no such thing as an IIA spoiler. I believe there is. Compute the winner. Start removing

RE: [EM] IRV in San Francisco

2004-11-16 Thread Paul Kislanko
Eric Gorr replied to my questions: At 3:14 PM -0600 11/16/04, Paul Kislanko wrote: No one can be added or removed from a ballot after the votes have been counted, Sure one can...just do it and recalculate. so by this distinction there is no such thing as an IIA spoiler. I believe

RE: [EM] IRV in San Francisco

2004-11-16 Thread Paul Kislanko
Eric Gorr asked a lot of questions So, you now believe there is such a thing as an IIA spoiler? I never said I didn't. I just said I couldn't get that there was from your definition: With IIA, the spoiler is a candidate that is either added or removed from the ballots. With ICC, the

[EM] Automatic Criterion Checking

2004-11-16 Thread bql
I wish we had nice clean definitions of our favorite criteria that were amenable to automatic checking. Then we just implement any new method in a few lines of code, and run the checker. In most cases I believe the computations could be completed in a few hours or a few days on any of our

Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)

2004-11-16 Thread bql
In a method that mistreats clones, a clone is an irrelevant alternative. Dropping a non-winning clone, allowing the other non-winning clone to win, violates the desired independence of irrelevant alternatives. Thus, everything that violates the clone criterion, violates independence of

RE: Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)

2004-11-16 Thread Paul Kislanko
YES! That's what I didn't have the right words to say. ICC is a subset of IIA is what I meant by ICC is a weaker formulation of IIA. Something can satisfy ICC but not satisfy IIA. The original question was how to define the word spoiler, and I've come to the conclusion that it cannot be used at

RE: [EM] Automatic Criterion Checking

2004-11-16 Thread Paul Kislanko
This is in fact, one of the great questions of mathematical logic. Unfortunately, 20 years before Arrow's theorem, there was Godel's Theorem, which proves that such an axiom-checker is as impossible as squaring the circle or simultaneously finding the position and momentum of an electron. You

RE: Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)

2004-11-16 Thread bql
On Tue, 16 Nov 2004, Paul Kislanko wrote: The original question was how to define the word spoiler, and I've come to the conclusion that it cannot be used at all without some qualification. An IRV-spoiler might be a clone or it might be an IA, and it can be one without being both. A spoiler is the

Re: Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)

2004-11-16 Thread Bart Ingles
[EMAIL PROTECTED] wrote: On Tue, 16 Nov 2004, Paul Kislanko wrote: The original question was how to define the word spoiler, and I've come to the conclusion that it cannot be used at all without some qualification. An IRV-spoiler might be a clone or it might be an IA, and it can be one without