candidate higher, or to cause a losing candidate to win by ranking that candidate lower? Consistency criterion—If the electorate is divided in two and a choice wins in both parts, does it always win overall? Participation criterion—Is voting honestly always better than not voting at all? (This is grouped with the distinct but similar Consistency Criterion in the table below.) Condorcet criterion—If a candidate beats every other candidate in pairwise comparison, does that candidate always win? (This implies the majority criterion, above) Condorcet loser criterion—If a candidate loses to every other candidate in pairwise comparison, does that candidate always lose? Independence of irrelevant alternatives—Is the outcome the same after adding or removing non-winning candidates? Independence of clones criterion—Is the outcome the same if candidates identical to existing candidates are added? Reversal symmetry—If individual preferences of each voter are inverted, does the original winner never win? Approval voting satisfies the mutual majority criterion and Smith criterion when voters' preferences are dichotomous; this is because the winner will be someone that the most voters prefer above all others, or that ties with other candidates but the group of tied candidates is preferred by more voters than any candidate not in the group. Variants and generalizations Some variants and generalizations of approval voting are: Multiwinner approval voting — multiple candidates may be elected, instead of just one. Fractional approval voting — the election outcome is a distribution - assigning a fraction to each candidate. Party-approval voting — voters approve of parties, rather than individual candidates. Combined approval voting — form of score voting with three levels that uses a scale of (-1, 0, +1) or (0, 1, 2). Score voting (also called range voting) — is simply approval voting where voters can give a wider range of scores than 0 or 1 (e.g. 0-5 or 0-7). D21 – Janeček method — limited to two approval and one negative vote per voter. See also Instant-runoff voting Notes References Sources External links Approval Voting Article by The Center for Election Science Could Approval Voting Prevent Electoral Disaster? Video by Big Think Approval Voting on Dichotomous Preferences Article by Marc Vorsatz. Scoring Rules on Dichotomous Preferences Article by Marc Vorsatz. The Arithmetic of Voting article by Guy Ottewell Critical Strategies Under Approval Voting: Who Gets Ruled In And Ruled Out Article by Steven J. Brams and M. Remzi Sanver. Quick and Easy Voting for Normal People