Talk:CDTT

It would be helpful to cite the paper where Woodall defines the criterion. James Green-Armytage 21:32, 19 May 2005 (PDT)

It's from a draft version of a paper that hasn't been published. Do you think this makes a difference? Kevin Venzke 11:33, 20 May 2005 (PDT)

Done, although I'm not sure how useful it is. User:KVenzke

I have deleted the following sentence: "Whichever of these methods is paired with the CDTT, the combined method necessarily fails the Plurality criterion and Condorcet criterion." In my opinion, this sentence ("... necessarily fails ...") could be interpreted as if CDTT, plurality, and Condorcet were incompatible. However, the Schulze method satisfies the CDTT criterion, the Plurality criterion, and the Condorcet criterion. Markus Schulze 23 Jun 2005

However, the Schulze method is not one of "these methods." The article should say that when the CDTT is "paired" with a method that satisfies LNHarm, Plurality and Condorcet are failed. Kevin Venzke 07:47, 23 Jun 2005 (PDT)

By the way, I changed that line from Regardless of the method paired with the CDTT, it should be noted that the combined method necessarily fails the Plurality criterion and Condorcet criterion, because Chris Benham criticized that this statement is only true with LNHarm methods, and that one could conceivably use the CDTT for some other reason. Kevin Venzke 07:51, 23 Jun 2005 (PDT)

Later No Harm? Minimal Defense?
The article says methods that satisfy CDTT satisfy Later No Harm only when there are 3 (or fewer) candidates. MAM and Schulze's method give identical results when there are 3 or fewer candidates, and neither MAM nor Schulze's method satisfies Later No Harm when there are 4 or more candidates. So why is the article suggesting a connection between CDTT and "coming close to satisfying" Later No Harm? SEppley 12:41, 11 March 2010 (UTC)

Similarly, it is not necessary to satisfy CDTT to satisfy Minimal Defense and the other related strategy criteria. (For instance, MAM satisfies those criteria.) CDTT is not really related to them. SEppley 12:47, 11 March 2010 (UTC)

Missing justification
Criteria need to be justified if they are to be taken seriously. What is the harm to society if society uses a voting method that does not satisfy CDTT? SEppley 12:41, 11 March 2010 (UTC)


 * Already in the pre-Woodall era, the CDTT criterion was discussed at the Election Methods mailing list under the name "beatpath GMC". The idea is: When the individual ballots can be completed in such a manner that candidate A is a Schwartz winner and candidate B is not a Schwartz winner and the individual ballots cannot be completed in such a manner that candidate B is a Schwartz winner and candidate A is not a Schwartz winner, then candidate B should not be elected. This guarantees that truncation doesn't needlessly lead to the election of a candidate outside the Schwartz set. Markus Schulze 22:26, 12 March 2010 (UTC)


 * Any chance someone can cook up a quick example to show this particular criterion at work? -- RobLa 04:59, 13 March 2010 (UTC)


 * See this mail. Markus Schulze 09:34, 13 March 2010 (UTC)