Talk:Schulze method

MinMax set and prudence criteria

Stubs for these 2 criteria would be nice too. --Wat 20

I tried to add a Column for MinMax to the table, but changing the template is not changing it on the Schulze Method page. Not sure why. Schulze Method passes MinMax criterion but Ranked Pairs (Tideman) does not, and this table should include that information to help differentiate the two. --Owen

Suggest Adding Later-No-Help and Later No-Harm (in comparison table)

It seems to me that Later-No-Help and Later-No-Harm should be added to the compliance table.

My reasoning: If these criteria were not important then a three-candidate election would be trivially solvable, but it is not.

We could omit LNH if we were only comparing Condorcet methods that all failed, for the purpose of identifying the differences between the Condorcet methods. But, if we are also comparing to plurality elimination systems (i.e. sequential runoff systems) such as IRV then we must include LNH Harm/Help (in the comparison table).

Filingpro (talk) 19:56, 13 January 2016 (UTC)

Adding later-no-harm would open a can of worms. Some election methods (e.g. anti-plurality or Coombs) are defined only for complete individual preferences. For other election methods (e.g. plurality voting or supplementary voting), it is disputed whether they satisfy later-no-harm. Markus Schulze 19:27, 14 January 2016 (UTC)

I think better to include known and highly relevant information, rather than exclude such information on account of unrelated and largely irrelevant issues.

I propose we add compliances with footnotes, if necessary, to address alternative reasoning.

Plurality
Later-No-Harm "Not Applicable", Later-No-Help "Not Applicable" - footnote: "Plurality voting allows the voter to choose only one candidate, so it is not possible to help or harm the chosen candidate by voting for secondary candidates. Plurality voting can be considered to pass both Later-No-Help and Later-No-Harm when considering that a voter's unexpressed secondary preferences can not help or harm their chosen candidate."

POST CORRECTION: Applying the same manner Anti-Plurality is treated for compliance with Reversal Symmetry in this article, Plurality does PASS both Later-No-Harm and Later-No-Help.Filingpro (talk) 03:01, 5 April 2016 (UTC)

Supplementary Vote:
Later-No-Harm PASS, Later-No-Help PASS - footnote: "A voter's supplementary vote can not help or harm their preferred candidate."

Coombs
Later-No-Harm FAIL, Later-No-Help FAIL - footnote: "When a truncated preference listing is considered to apportion last place votes among all unranked candidates, a voter may help or harm their preferred candidates by ranking additional ones."

Anti-Plurality
Later-No-Harm FAIL, Later-No-Help PASS - footnote: "When a voter having an ordered preference of the candidates is considered to vote for all candidates other than their least preferred, their vote for any later preferred candidate may harm but not help any earlier candidate."

POST CORRECTION: My error; Anti-Plurality does FAIL Later-No-Help because the probability of a preferred candidate being elected can increase as later preference are added to the ballot (by increasing the probability of an opponent being listed last).Filingpro (talk) 03:01, 5 April 2016 (UTC)

ALTERNATIVE SOLUTION 1: Remove potentially controversial, esoteric and less common methods from table, such as Coombs, Anti-Plurality.

ALTERNATIVE SOLUTION 2: Create two tables (1) "Comparison To Other Condorcet Methods" (2) "Comparison To Methods Commonly Used For Government Elections"

I believe Schulze is a compelling resolution method and should be considered seriously against other real-world government election systems (e.g. Top-Two Runoff, IRV). In my view, without including Later-No-Harm/Help we make no less than a mockery of the comparison.

Filingpro (talk) 05:25, 17 January 2016 (UTC)

A comparison table with your recommended additions already exists at Voting_system#Evaluating_voting_systems_using_criteria (scroll down past the text). That table is heavily peer-reviewed, and contains lots of the kinds of clarifications you suggest. The table on this page is just a subset of that table. VoteFair (talk) 19:40, 22 January 2016 (UTC)

(1) The table here is not a mere subset of the table on the main voting article, because it contains many voting methods not included in the main voting article, especially ones cited by Markus Schulze as being problematic for inclusion of Later-No-Harm such as Coombs, Anti-Plurality, Supplemental Vote. I count at least six other methods not in the main article.

(2) If the criterion are "just a subset" of the main table, what is our editorial reasoning for which criteria we include? How would the reader know that we are excluding critically important criteria, such as Later-No-Harm and Later-No-Help? Without this disclosure the reader is provided an entirely invalid "comparison of voting systems". Also, if the determinations from the main table are peer-reviewed, then why would they not propagate here? It would seem more logical to include important criteria, rather than include esoteric voting methods not included in the main voting article. Filingpro (talk) 10:14, 19 March 2016 (UTC)

PROPOSED REMEDIES: If the goal is to compare Schulze to more esoteric methods without introducing Later-No-Help/Harm controversy, for the purpose of offering information different than the main article, this goal should not trump comparing Schulze to common real-world methods in a meaningful way. OPTION 1: Keep the existing table and re-title it appropriately. Create a second table "Comparison To Methods Commonly Used For Government Elections". Include Plurality, Top-Two Runoff, IRV (perhaps others). Use criteria that distinguish the methods' performance, e.g. Monotonic, Mutual Majority, Condorcet, Condorcet Loser, Clone Independence, Participation, Later-No-Harm, Later-No-Help, Summability.
OPTION 2: Clarify what is excluded from this table and provide a link to the main comparison table. "The following table compares the Schulze method with other preferential single-winner election methods using some but not all known voting criteria. For a complete comparison of Schulze to commonly used election methods, including strategic voting criteria such as Later-No-Harm and Later-No-Help, refer to the voting methods comparison chart. (link)
Filingpro (talk) 10:14, 19 March 2016 (UTC)

Creating one table for "esoteric methods" and one table with other criteria for "methods commonly used for government elections" would be weaseling. We would apply different standards for different methods. Furthermore, the allegedly omitted criteria are already mentioned in the section "Failed criteria" of the Schulze method article. Markus Schulze 14:38, 19 March 2016 (UTC)

(1) The source of weaseling is the existing article "Comparison of voting systems" which implies it is a complete comparison, which it is not. The table is sorted by performance, to emphasize better performing methods, yet criteria are omitted which weasel the results. The double standard is the existing article which introduces criteria on the one hand, but then selectively applies certain criteria and not others.

(2) The original remedy I proposed addresses the source of the problem by adding LNH/LNH. On what basis is the determination of "Reversal Symmetry" and "Clone Proof" for Coombs, Anti-Plurality less controversial than of LNHarm/Help? Where is the "peer-reviewed" source for these determinations? Filingpro (talk) 20:13, 19 March 2016 (UTC)

Based on responses here, I believe the best remedy: We put the LNH determinations here as either YES/NO, and see if a controversy exists. I see no evidence given that the LNH/Harm determinations are provided in the main table. Those controversies can be resolved in the main table and propagated here. If methods are not included in the main table for lack of significance or because their determinations are unknown, they should not be included here, forcing the removal of critical and known information, ultimately misrepresenting the relative performance of Schulze and other methods.
Filingpro (talk) 20:13, 19 March 2016 (UTC)
ALTERNATE REMEDY: STEP 1. Change title to "Partial Comparison of Voting Systems"* STEP 2. Remove any method from the table that is known to pass either Later-No-Help, Later-No-Harm, or Favorite Betrayal. Since Schulze fails all three, the remaining methods in the table would provide an accurate comparison of performance. This would be of usefulness to the reader. Filingpro (talk) 21:00, 19 March 2016 (UTC)
*IMPORTANT NOTE: This latter remedy is akin to my earlier solution "Comparison To Other Condorcet Methods". A second table "Comparison to Runoff Systems" or "Comparison To Positional Voting Systems" would not be warranted as that would be better placed in a general article regarding Condorcet or Positional methods, unless Schulze's Condorcet method's performance is particularly unique. Filingpro (talk) 22:07, 19 March 2016 (UTC)
Or, what is the goal of the table, as opposed to the main article table? For example, the goal might be to compare Schulze performance with respect to global criteria (i.e. non-strategic), as introduced by Woodall http://www.votingmatters.org.uk/ISSUE3/P5.HTM This would remove Monotonic, Participation, Later-No-Help/Harm etc. The table could be appropriately titled. Filingpro (talk) 23:39, 19 March 2016 (UTC)

Dear Filingpro, you ask: "On what basis is the determination of 'Reversal Symmetry' and 'Clone Proof' for Coombs, Anti-Plurality less controversial than of LNHarm/Help?" The presumptions of the reversal symmetry criterion and the independence of clones criterion can be applied to Coombs and anti-plurality. Therefore, it can be checked whether these methods satisfy these criteria. On the other side, the presumptions of later-no-help and later-no-harm cannot be applied to Coombs and anti-plurality, because Coombs and anti-plurality are defined only for complete individual rankings. Therefore, it cannot be checked whether Coombs and anti-plurality satisfy later-no-help or later-no-harm. Markus Schulze 06:58, 20 March 2016 (UTC)

Yes I see the distinction however at this point I see this particular question as a red herring, and therefore I retract it (despite my conjecture Later-No-Help/Harm can indeed be logically applied to Coombs and Anti-plurality, under a unified model). Meanwhile the article misrepresents the performance comparison of Schulze against methods that pass Later-No-Help, Later-No-Harm. To make progress on this issue, please respond or concur with remedy above "ALTERNATE REMEDY" and the question ascertaining the very goal of the table itself. In short, we can omit LNHarm/Help which Schulze fail, but we can not also include methods that pass LNHarm/Help in a performance comparison and call it a valid comparison. These methods can be properly compared in the main voting system table. Please let me know if you have any questions. Thank you Filingpro (talk) 08:12, 20 March 2016 (UTC)

Dear Filingpro, first of all, there isn't even an article on later-no-help. When you are so obsessed by later-no-help, then the first thing that you should do is to create an article on later-no-help.

Second, whether Coombs and anti-plurality satisfy later-no-harm is discussed neither at the Coombs article nor at the anti-plurality article nor at the later-no-harm article. But you want to discuss your "unified model" (that allegedly tells us how later-no-harm could be applied to Coombs and anti-plurality) at great length at the Schulze method article! That's ridiculous! How later-no-harm could be applied to Coombs and anti-plurality should first be discussed at the Coombs article, the anti-plurality article and/or the later-no-harm article. Markus Schulze 09:25, 20 March 2016 (UTC)

I believe you almost entirely misread my last statement. I am now simply suggesting that methods for which Later-No-Harm is passed and undisputed, such as IRV, we remove them from your table. If you like, we can treat Later-No-Help separately. Regards Filingpro (talk) 10:54, 20 March 2016 (UTC)

Waiting for response 1-2 weeks before removing (see underline above). Please let me know if you would like further clarification. Thanks Filingpro (talk) 04:40, 21 March 2016 (UTC)

Dear Filingpro, I will classify your behavior as vandalism. Markus Schulze 06:44, 21 March 2016 (UTC)

Dear Markus Schulze, you are an esteemed contributor to the field of social choice, and I am grateful for your contributions: the Schulze method, voting publications, and wiki contributions. I will do my best to be respectful in any editorial deliberation with you, and I apologize if I have been disrespectful here.

It seems to me there is a misunderstanding. I will start a new section below clarifying my editorial issue with the article. Kindly Filingpro (talk) 06:09, 24 March 2016 (UTC)

RfC: Incomplete Comparison Of Runoff Systems To Schulze In Compliance Table (Requesting Removal)

UPDATE: A solution posted to the article - see new section below "Later-No-Harm/Help Added To Table" Filingpro (talk) 20:56, 10 April 2016 (UTC)

It is axiomatic to a compliance table each method added is a direct comparison to each other method.

In deciding which method to use for a three way election, the reader would not be given adequate information in the comparison table to make an informed choice between Schulze and runoff systems (e.g. IRV), because nearly every criteria Schulze satisfies is revealed, but Later-No-Harm and Later-No-Help are omitted, which IRV satisfies and Schulze does not, and which are fundamental to their differentiation.

Since the comparison does not provide for an informed choice, I suggest we remove runoff methods from the table. Schulze is better compared to runoff systems in the main voting article's compliance table.

The counterargument to this proposal I do not find persuasive, that Schulze's failure of LNH is mentioned earlier in the article.

Problem 1: Proper treatment of a subject in one area does not justify improper treatment in another.

Problem 2: If the criterion is important enough to cite Schulze's failure, it is only more important in the direct comparison to reveal runoff systems pass, or to simply not include them in the table.

I have not yet heard justification for why runoff systems must be included in this comparison table, specifically in the Schulze article, which contains only a subset of the criteria. I believe the reader is well served in this article by seeing a direct comparison between Schulze and other simultaneous election methods, but not against sequential runoff systems whose relative performance is misrepresented here (albeit inadvertently).
Filingpro (talk) 06:54, 24 March 2016 (UTC)

• Schulze is compared against instant-runoff because they solve the same problem, choosing a winner from preference ballots. It would make no sense to have a comparison of such methods and omit one of the main alternatives. If the comparison is missing some important properties then they can be added. —David Eppstein (talk) 15:53, 24 March 2016 (UTC)

Thank you David Eppstein for joining and contributions to the field. The remedy you propose was also my starting point (section above "Suggest Adding Later-No-Help and Later No-Harm"). The problem is some editors claim LNHarm is disputed for Coombs, Anti-plurality (see editor Schulze comment below). Editorial priority is currently given to including these methods, and to omit the Later-No-Harm/Help criterion. Can you please advise how we might remedy this problem? In your reply you suggest IRV is a "main alternative" and LNHarm/Help are "important properties" to which I agree. Should we...

(A) Remove Anti-Plurality/Coombs due to controversy (and less relevance) and add Later-NoHarm/Help?

(B) Keep all methods while adding LNHarm/Help, and if so can you tell us how to complete the compliances?

(C) Remove sequential runoff methods from table (or non-condorcet methods), providing the reader an accurate comparison of Schulze to other simultaneous methods (or Condorcet methods), distinguishing the table from the main voting article table, providing added value?

(D) Leave the direct performance comparison between Schulze and IRV in the table without including LNHarm/Help?

(E) Other?

In my view, "D" is not acceptable because any comparison of a simultaneous voting method such as Schulze to a sequential runoff method, without inclusion of Later-No-Harm is a false comparison. Since we would not justify making this false comparison on its own, we can not justify the false comparison merely for external reasons (i.e. disputes re Coombs/Anti-Plurality - not used in elections or not as commonly used).

The current article does not to include rating ballot methods (Approval, Range, Majority Judgment etc.), despite they “solve the same problem”. Why then can we not remove sequential runoff methods (or remove controversial and esoteric methods which can't be evaluated with respect to "important criteria"- added Filingpro (talk) 21:06, 26 March 2016 (UTC)), unless they can be properly compared? Also, what should be the editorial goal of this table, as opposed to the compliance table in the main voting article, where IRV and Schulze are properly compared? Thanks for any recommendations. Filingpro (talk) 19:47, 26 March 2016 (UTC)

• Adding later-no-harm to the table would open a can of worms, because later-no-harm isn't really a well-defined criterion. This can best be seen by the large number of election methods for which it is disputed whether they satisfy or violate later-no-harm. For some methods, this is disputed because these methods are defined only for complete individual preferences (e.g. Coombs, anti-plurality). For some methods, this is disputed because these methods don't allow voters to cast more than a limited number of preferences (e.g. plurality voting, supplementary voting). For some methods, this is disputed because there are different ways how these methods could be generalized to situations with incomplete individual preferences; for example, the Minimax Condorcet article says: "When the pairwise opposition variant is used, Minimax also does not satisfy the Condorcet criterion. However, when equal-ranking is permitted, there is never an incentive to put one's first-choice candidate below another one on one's ranking. It also satisfies the Later-no-harm criterion, which means that by listing additional, lower preferences in one's ranking, one cannot cause a preferred candidate to lose." However, removing instant-runoff voting from the table is not an appropriate answer to the problems of later-no-harm, because then everybody could propose a lousily defined criterion for his favorite election method and then demand a special treatment for his favorite method. Markus Schulze 19:45, 24 March 2016 (UTC)

• Comment. I can understand the article, but I cannot understand this RfC. What is a "compliance table"? What is a "runoff method"? These phrases do not occur in the article. And what is "the table" in the underlined proposal? Maproom (talk) 07:56, 26 March 2016 (UTC)

• With "compliance table" or "the table", Filingpro means this table. With "runoff method", Filingpro means instant-runoff voting. Basically, this RfC says that instant-runoff voting should be removed from this table because instant-runoff voting satisfies later-no-harm while it is not possible to say which of the other methods satisfies later-no-harm. Markus Schulze 10:35, 26 March 2016 (UTC)

• To my mind that is a really bad reason for removing it from the table. —David Eppstein (talk) 20:15, 26 March 2016 (UTC)

Could you reply to my response above and offer argumentation for "bad" if still applicable, because while I agree with much of editor Schulze wrote above, I don't agree entirely with the statement of my "reason" which you seem to be responding to. Would it be fair to ask you to comment on my statement of the problem (above - see A, B, C, D, E) rather than Schulze since I am raising the issue? I don't agree with the statement of my reason as provided here (while I do not suggest Schulze intending to misrepresent but only to clarify) Kindly Filingpro (talk) 21:22, 26 March 2016 (UTC)

To David Eppstein, put another way, you said Later-No-Help/Harm are "important criteria" and should be added. Do you suggest remedy (A) or (B) in my response further above? Thanks for any help you can provide. Filingpro (talk) 22:44, 26 March 2016 (UTC)

I did not say that LNH is important. What I said was that, if the table is missing important criteria, then the correct fix is to add columns, not to delete rows. —David Eppstein (talk) 23:21, 26 March 2016 (UTC)

Thank you for clarification. Apologies for misrepresentation. I believe we must address the concerns of editor Schulze before adding columns. Based on your helpful feedback I have a new proposal below. Filingpro (talk) 01:46, 27 March 2016 (UTC)

NEW PROPOSAL:

I believe the following proposal builds upon the feedback from all editors, and improves the article.
ARGUMENTATION: We do not include voting systems having different ballot types than Schulze (Approval, Majority Judgment) because they are not subject to the same criteria. We must be be consistent. Schulze method operates on truncated preference ballots. Coombs and Anti-Plurality do not. These require different input. I believe this to be the central problem.
ACTION: (1) I will add an article for Later-No-Help (2) We update the Schulze article table adding LNHarm and LNHelp and include voting systems that accept the same input as Schulze - i.e. truncated preference listings, so that we make a fair and complete comparison of methods of the same type. (Note: Plurality and various Two-Round Runoff systems operate on truncated preference input)
Filingpro (talk) 01:46, 27 March 2016 (UTC)

• Dear Filingpro, and what do you do about the fact that it is disputed for many election methods whether they satisfy or violate later-no-harm or later-no-help? Markus Schulze 08:20, 27 March 2016 (UTC)

As this article is specifically on the Schulze method, and because Schulze accepts as input a truncated preference listing, I propose we include all methods in the table that can operate unambiguously on a truncated preference listing, so that we make a fair and complete comparison of methods of the same type as Schulze. Do you agree that any method that can unambiguously receive as input a truncated preference listing also has knowable determinations for Later-No-Help and Later-No-Harm? To be clear, this would mean that Anti-Plurality is not included in the table just as we do not include Range Voting etc., because neither accepts as input truncated preference listings, as Schulze does. My opinion is that by making complete and legitimate performance comparison of Schulze to every known truncated preference method, while including Later-No-Harm and Later-No-Help criterion (which are defined precisely for truncated preference methods like Schulze), then the accuracy and credibility of a Schulze performance comparison is enhanced. This would give the reader a very clear view of how these truncated methods actually compare to each other in performance. It is my view, that comparing Schulze to other methods of the same type but excluding important criteria (whose compliance is in fact unambiguous), damages the comparison and damages the legitimacy of the table. In my opinion it would be a mistake for us to force inclusion of other methods that require different ballot types as input (e.g. Coombs), to justify removing important criteria, thereby delegitimizing the comparison of methods that do have the same type, particularly methods deemed as "main" methods. I believe we are likely in agreement about voting theory, while this is an editorial issue. Thank you for your question and engaging in the discussion. I am hoping you will see this as an optimal solution to both of our concerns that presents Schulze method in the most accurate and complete way possible. I would begin by creating an article for Later-No-Help as you suggested before making any edits. Regards Filingpro (talk) 11:36, 27 March 2016 (UTC)

Dear Filingpro, your proposals are not acceptable. You are weaseling to get somehow some special treatment for instant-runoff voting. Markus Schulze 16:31, 27 March 2016 (UTC)

I will add Later-No-Help article and then propose a new RfC for editors to comment on two possible tables. My goal is to improve the Schulze article, by providing a more accurate performance comparison of Schulze to methods of the same type, by including applicable criteria that are fundamental to a reader making an informed choice. Respectfully Filingpro (talk) 18:38, 27 March 2016 (UTC)

If you like, you can clarify your position now for the upcoming RfC, so that when I post the RfC your position is correctly represented, below...

Upcoming RfC question to editors: Should we:

(A) Include Later-No-Harm/Help and exclude Coombs/Anti-plurality, or

(B) Include Coombs/Anti-plurality and exclude Later-No-Harm/Help?

My argument for A is the reader is better served by making a more complete comparison of Schulze to every known method of the same type - i.e. that receive as input a truncated preference listing, rather than include Coombs/Anti-Plurality which require different input and therefore not subject to the same criteria.

Your argument for B is the reader is better served by comparing Schulze to Coombs/Anti-pluralty to include more methods, rather than include Later-No-Harm/Help, which is not knowable for these methods. Including Later-No-Harm/Help over inclusion of Coombs/Anti-Plurality is weaseling to promote methods that pass these criteria.

Is that an accurate summary of your argumentation? Thanks for any clarification. Regards Filingpro (talk) 18:38, 27 March 2016 (UTC)

Dear Filingpro, if I understand you correctly, then proposal (B) implies that instant-runoff voting should be removed from the table. Both proposals, (A) and (B), are not acceptable. Again, I will consider your edits as vandalism. Markus Schulze 20:33, 27 March 2016 (UTC)

Proposal (B) includes IRV (same table as now). Filingpro (talk) 15:36, 28 March 2016 (UTC)

QUESTION 1 for Markus Schulze re: Anti-Plurality failure of Reversal Symmetry. You say "presumptions of the reversal symmetry criterion...can be applied to ...anti-plurality." Reversal symmetry presumes a voter preference ballot. To apply these presumptions to a "Vote Against" ballot which only records the voter's most opposed candidate, we are not using a literal "Vote Against" ballot, instead we are assuming the voter is required to submit a complete preference listing (e.g. abc by writing them sequentially as Woodall suggests). Is that correct? Filingpro (talk) 15:36, 28 March 2016 (UTC)
QUESTION 2 for Markus Schulze - What is our editorial standard for determining compliances, with respect to hypothetical challenges of WP:OR? For example, there is no mention of the failure of Anti-Plurality to satisfy Reversal Symmetry in either article on Wikipedia, nor is there a citation in Schulze article. Is that correct? If so, then is the standard whether we can logically apply the voting method to the presumptions of the criteria (e.g. taking liberty to change the ballot to match the presumptions), and if the results are mathematically computable? Is that correct? Filingpro (talk) 15:36, 28 March 2016 (UTC)

Dear Filingpro, here is the difference: On the one side, it is possible to check whether Coombs and anti-plurality satisfy or violate reversal symmetry simply by looking at the definitions and without having to make additional presumptions. On the other side, it is not possible to check whether Coombs and anti-plurality satisfy or violate later-no-harm simply by looking at the definitions and without having to make additional presumptions. You claim that you have a "unified model" (that allegedly tells us how later-no-harm could be applied to Coombs and anti-plurality). But your "unified model" is original research, at best. Markus Schulze 16:10, 28 March 2016 (UTC)

(1) I never suggested proposing a "unified model" in Wikipedia (you will see this was a parenthetical remark - i.e. merely a conjecture that one exists)

(2) In QUESTION 1, I am asking specifically how we arrive at Anti-Plurality failure of Reversal Symmetry in the Schulze article. Can you please answer? Filingpro (talk) 02:04, 29 March 2016 (UTC)

• It seems to me having a table that compares the subject of the article to some instant-runoff voting methods but not all could be misleading. It might leave a false impression about the primacy on utilitarian criteria of a particular method. If I'm understanding the subject matter correctly LNH can be determined for some methods. Therefore, it seems you'd add the column note those methods where it can be determined with the appropriate notation and for those where it cannot be determined have that as a notation. Klaun (talk) 23:55, 28 March 2016 (UTC)

Generally agreed.

Clarification: My "UPDATED PROPOSAL" above includes all runoff methods, and every known voting method capable of receiving the same input as Schulze, so all criteria that apply to one apply to all, making an accurate comparison. The problem occurs when we start introducing methods that require different input, and then controversies arise as to how criteria are applied. You will notice, for example, no editor is demanding to add voting systems to this table that receive as input scoring, rating, and approvals, because their behaviour with respect to the criteria can be less clear, and dilutes the focus of the article. What I object to, is that we have added two rather obscure (i.e. unused) methods to the table that have different input requirements than Schulze, and consequently we exclude criteria which are fundamental to comparing Schulze to other main methods (and also shows Schulze more favorably - in fact Schulze is a near perfect voting method, buts its primary weakness is its failure of the criteria that are excluded from its comparison).

Your suggestion of distinguishing compliances that can not be determined and making notations is I think worth considering (also my initial inclination when I first proposed adding LNH) although raises editorial questions as to where we source these determinations etc. and whether they are better resolved first in the main voting article compliance table or in the articles for the various methods and criteria. Thanks for any suggestions. Filingpro (talk) 03:10, 29 March 2016 (UTC)

Comment: Original rationale seems very odd and weak to me. The current article places no WP:UNDUE weight on the strengths of the method, nor does it avoid all criticism. LN(harm/help) are very interesting of course, but their lack of current inclusion is not some unfair bolstering of Schulze method. Revised proposal (which I put in new section) seems much better, and I do like the idea to only include methods that use the same input. IRV in this sense is comparable to Schulze method. I advise OP and others to be wary of moving the goalposts re: this current RfC. Participation by Mr. Schulze here is is interesting. While his expertise is appreciated I will also remind myself that he is clearly highly WP:INVOLVED. While I believe him that it is contested whether certain methods comply with LNH, I'm not sure that I understand his comment that it "isn't really a well-defined criterion". I understand that (non)compliance is hard to rigorously prove, but our article at least makes the definition of the criterion seem clear, simple, and uncontested. This may or may not matter much for the current discussion. At present I don't see the problem with including a LNH column in the table. The fact that many methods would have a blank or N/A under LN(harm/help) due to lack of RS is also not a big problem in my opinion. SemanticMantis (talk) 14:02, 4 April 2016 (UTC)

Generally agreed regarding remedies. This was my very first proposal "Add L-N-Harm/Help" long before RfC by Schulze. Consensus seems to be building around adding columns. Filingpro (talk) 23:00, 5 April 2016 (UTC)

Let's say that there are five candidates (A,B,C,D,E). Let's say that the sincere opinion of a voter is A>B>C>D>E. That means that this voter prefers A to B to C to D to E. Now, what does it mean when we say that this voter casts one preference or two preferences?

Supporters of instant-runoff voting usually presume that voters have strong preferences on who is the best candidate, but that the voters are rather indifferent on who is the worst candidate. Therefore, a supporter of instant-runoff voting will argue that a voter who casts only one preference is a voter who votes A>B=C=D=E and a voter who casts two preferences is a voter who votes A>B>C=D=E.

Supporters of Coombs usually presume that voters have strong preferences on who is the worst candidate, but that the voters are rather indifferent on who is the best candidate. Therefore, a supporter of Coombs will argue that a voter who casts only one preference is a voter who votes A=B=C=D>E and a voter who casts two preferences is a voter who votes A=B=C>D>E.

Both, the instant-runoff supporters and the Coombs supporters, claim that only their method has the property that casting a weaker preference can never hurt or help a stronger preference. The whole argumentation is arbitrary. The difference between these two methods is not that the one has this property and the other doesn't. They only differ in which preferences they believe to be stronger. Markus Schulze 18:21, 5 April 2016 (UTC)

I see how Coombs or any method could use a reverse order ballot, but that would mean Coombs fails Woodall's Majority, which it does not. Our table applies input with same polarity to each method so results have meaning. For example, for Anti-Plurality we assume rankings are in preferred order. Filingpro (talk) 22:43, 5 April 2016 (UTC)

What does "polarity" mean in this context? Markus Schulze 04:33, 6 April 2016 (UTC)

In Woodall's framework, the listing abc denotes the voter places a first, b second, c third etc. On a reverse order ballot, without normalizing the input, 'a' in Woodall's listing would be least preferred by the voter rather than first preferred (i.e. opposite meaning). The polarity means the direction of the voter's ordinal preferences in the listing. If we reverse the polarity, Schulze fails Woodall's Majority and Condorcet, which it does not. Filingpro (talk) 21:35, 6 April 2016 (UTC)

Dear Filingpro, the question is not whether the individual voter ranks the candidates from most preferred to least preferred or from least preferred to most preferred. The question is whether the individual voter has strong preferences between his most preferred candidates or strong preferences between his least preferred candidates. Supporters of instant-runoff voting presume that the individual voter has strong preferences between his most preferred candidates and weak preferences between his least preferred candidates.

(Re: Coombs) I believe you suggest Woodall's “later preference” for Coombs means more preferred by the voter, rather than less preferred? The problem I see is then Coombs fails Woodall's Majority. Do you see the problem? Filingpro (talk) 20:04, 7 April 2016 (UTC)

Your claims about the Schulze method are incorrect. The Schulze method only presumes that the individual voter casts a strict weak order. Furthermore, the Schulze method satisfies reversal symmetry. Therefore, reversing the "polarity" has no impact on the result of the elections. Markus Schulze 04:58, 7 April 2016 (UTC)

I said if the voter's least preferred choice is first (instead of last) in Woodall's preference listing, then Schulze fails Woodall's Majority and Condorcet, which leads to a contradiction. Does that make sense? If the Schulze analogy is confusing, I suggest we discuss Coombs (please see comment above). Filingpro (talk) 20:04, 7 April 2016 (UTC)

Dear Filingpro, even when the voters rank the candidates from most preferred to least preferred, a voter can have a strong opinion on who is the worst candidate and be rather indifferent on who is the best candidate. For example: A voter could say that Trump shouldn't be elected; at the same time, this voter could have no strong opinion on whether Cruz or Kasich should win. Does that make sense to you? Markus Schulze 04:17, 8 April 2016 (UTC)

Of course but what is the point you want to make about LNH? What I'm saying is for the voter you describe, Woodall's "later preference" means Trump is later than Cruz & Kasich in Woodall's preference listing. Just as in Anti-Plurality, we consider the compliance by assuming a complete listing whereby the candidate at the end of the listing is voted against. Filingpro (talk) 07:08, 9 April 2016 (UTC)

Oh, wow, that's perverse. Thanks Markus, I get it now. I thought we just didn't allow votes like A>B=C=D=E. The vote should either be full, e.g. A>B...>E or it gets truncated to e.g. A>B if the form is not completed. Anyway, I don't think this in and of itself is a strong reason to not have LNH in the table. Maybe you could put sufficient warnings and critiques in the LNH articles to better illustrate their potential problems and potential for ill definition. 14:36, 6 April 2016 (UTC)

Agreed. Filingpro (talk) 20:04, 7 April 2016 (UTC)

UPDATE: A solution posted to the article - see new section below "Later-No-Harm/Help Added To Table" Filingpro (talk) 20:56, 10 April 2016 (UTC)

Later-No-Harm/Help Added To Table

Added columns Later-no-harm and Later-no-help without removing methods as per general consensus.

We disclose clearly the assumptions made for compliances of Anti-Plurality, Coombs, and Dodgson, and importantly we make clear the assumptions for non-applicability, so the reader can decide for themselves.

I believe this disclosure addresses any WP:OR problem, while we advance no new theory, only how we normalize the inputs in the table so all methods receive the same input.

By doing so we better distinguish the methods, and the compliances are obviously consistent with observable behavior. For example, Anti-Plurality, Coombs, and Dodgson are vulnerable to burying; their failure of Later-No-Help distinguishes them from compliant methods.

I believe this is better than using ‘NA’ in the table. Filingpro (talk) 20:48, 10 April 2016 (UTC)

Ordering Columns In Compliance Table

I suggest we list criteria first by winner selection, then strategic voting, then strategic nomination, then counting:

Majority
Majority Loser
Mutual Majority
Condorcet
Condorcet Loser
Smith
Reversal Symmetry
Participation, Consistency
Monotonicity
Later-no-harm
Later-no-help
Clone Independence
ISDA
LIIA
Polynomial Time
Resolvability

We sort by number of compliances, and secondary sort by compliances left to right. We can put Schulze at top as long as table correctly titled. Filingpro (talk) 21:05, 10 April 2016 (UTC)

Complete garbage

Sorry Schulze, you're completely obtuseness to include the "Tennessee example" and stubbornly stick with this obscure spiderweb map makes this method all but incomprehensible to all but the greatest autists. Sad really, as this would be an excellent method to elect single winner executive positions over IRV. And you wonder why the two round system/IRV/STV are used the world over infinitely more than your still confusing method. — Preceding unsigned comment added by 64.66.22.220 (talk) 19:09, 12 May 2016 (UTC)

As Albert Einstein said: "Make things as simple as possible, but not simpler." Markus Schulze 09:04, 13 May 2016 (UTC)