Distributed Score Voting: Difference between revisions

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(Starting release)
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Graphically, each candidate is a node; the head-to-head is represented by an arrow, leaving the winning candidate, entering the losing candidate. The tie is represented as a double arrow entering, that is both candidates are considered losers.
Graphically, each candidate is a node; the head-to-head is represented by an arrow, leaving the winning candidate, entering the losing candidate. The tie is represented as a double arrow entering, that is both candidates are considered losers.


2) Find the smallest set X (Smith set) of nodes that don’t have incoming arrows, coming from outside the set.
2) Find the smallest set X ([[Smith set]]) of nodes that don’t have incoming arrows, coming from outside the set.


Then remove all candidates not in X from the votes.
Then remove all candidates not in X from the votes.


3) Convert the votes into a range form, assigning 0 points to the candidates with the lowest score and normalizing* the remaining candidates, using the following formula:
3) Convert the votes into a range form, assigning 0 points to the candidates with the lowest score and normalizing the remaining candidates, using the following formula:


M = candidate with the highest score, before normalization.
M = candidate with the highest score, before normalization.
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By repeating this process several times, you can get as many winners as you like, which will be those removed in point 5.
By repeating this process several times, you can get as many winners as you like, which will be those removed in point 5.


6) If you want to know the % of victory of the winning candidates then, in each original vote, you must remove all the candidates who haven’t won, and normalize* the vote with the formula used in point 3 (with W=100 fixed). The sum of points for each candidate will indicate the % of victory.
6) If you want to know the % of victory of the winning candidates then, in each original vote, you must remove all the candidates who haven’t won, and normalize the vote with the formula used in point 3 (with W=100 fixed). The sum of points for each candidate will indicate the % of victory.



===Head-to-head===
===Head-to-head===
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Criteria met by DSV:
Criteria met by DSV:


* Majority criterion
*[[Majority criterion]]
* Majority loser criterion
*[[Majority loser criterion]]
* Mutual majority criterion
*[[Mutual majority criterion]]
* Condorcet criterion
*[[Condorcet criterion]]
* Condorcet loser criterion
*[[Condorcet loser criterion]]
* Smith criterion
*[[Smith criterion]]
* Independence of irrelevant alternatives
*[[Independence of irrelevant alternatives]]
* Independence of clones criterion
*[https://en.wikipedia.org/wiki/Independence_of_clones_criterion Independence of clones criterion]
* Monotonicity criterion
*[[Monotonicity criterion]]
* Reversal symmetry
*[https://en.wikipedia.org/wiki/Reversal_symmetry Reversal symmetry]
* Pareto criterion
*[[Pareto criterion]]


Criteria not met by DSV:
Criteria not met by DSV:


* Participation criterion
*[[Participation criterion]]
* Consistency criterion
*[[Consistency criterion]]
* Later-no-harm criterion
*[[Later-no-harm criterion]]
* Later-no-help criterion
*[[Later-no-help criterion]]
* Favorite betrayal criterion
*[[Favorite betrayal criterion]]


The first two criteria not met are derived mainly from the fact that DSV wants to ensure the victory of the candidate who wins all the head-to-head (when it exists).
The first two criteria not met are derived mainly from the fact that DSV wants to ensure the victory of the candidate who wins all the head-to-head (when it exists).
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This type of tactical vote works only if:
This type of tactical vote works only if:
* there is a condorcet paradox which includes at least 4 candidates.
* there is a [[Condorcet paradox]] which includes at least 4 candidates.
* through the tactical vote, the candidate who should have been the winner can be taken out of the Smith set.
* through the tactical vote, the candidate who should have been the winner can be taken out of the [[Smith set]].
* the new winner is actually a better candidate than the previous one (the new winner in the example could also be C).
* the new winner is actually a better candidate than the previous one (the new winner in the example could also be C).
* the voter has a fairly precise knowledge of the likely ballots result, without which this tactical vote would turn against him.
* the voter has a fairly precise knowledge of the likely ballots result, without which this tactical vote would turn against him.