Independence of clones criterionIn voting systems theory, the independence of clones criterion measures an election method's robustness to strategic nomination. Nicolaus Tideman was the first to formulate this criterion, which states that the winner must not change due to the addition of a non-winning candidate who is similar to a candidate already present. To be more precise, a subset of the candidates, called a set of clones, exists if no voter ranks any candidate outside the set between (or equal to) any candidates that are in the set.
Participation criterionThe participation criterion is a voting system criterion. Voting systems that fail the participation criterion are said to exhibit the no show paradox and allow a particularly unusual strategy of tactical voting: abstaining from an election can help a voter's preferred choice win. The criterion has been defined as follows: In a deterministic framework, the participation criterion says that the addition of a ballot, where candidate A is strictly preferred to candidate B, to an existing tally of votes should not change the winner from candidate A to candidate B.
Smith criterionThe Smith criterion (sometimes generalized Condorcet criterion, but this can have other meanings) is a voting systems criterion defined such that it's satisfied when a voting system always elects a candidate that is in the Smith set, which is the smallest non-empty subset of the candidates such that every candidate in the subset is majority-preferred over every candidate not in the subset. (A candidate X is said to be majority-preferred over another candidate Y if, in a one-on-one competition between X & Y, the number of voters who prefer X over Y exceeds the number of voters who prefer Y over X.
Minimax Condorcet methodIn voting systems, the Minimax Condorcet method (often referred to as "the Minimax method") is one of several Condorcet methods used for tabulating votes and determining a winner when using ranked voting in a single-winner election. It is sometimes referred to as the Simpson–Kramer method, and the successive reversal method. Minimax selects as the winner the candidate whose greatest pairwise defeat is smaller than the greatest pairwise defeat of any other candidate: or, put another way, "the only candidate whose support never drops below [N] percent" in any pairwise contest, with N as high as possible.
Strategic votingStrategic voting, also called tactical voting, sophisticated voting or insincere voting, occurs in voting systems when a voter votes for a candidate or party other than their sincere preference to prevent an undesirable outcome. For example, in a simple plurality election, a voter might gain a better outcome by voting for a less preferred but more generally popular candidate. Gibbard's theorem shows that all single-winner voting methods encourage strategic voting, unless there are only two options or dictatorial (i.
Nanson's methodThe Borda count electoral system can be combined with an instant-runoff procedure to create hybrid election methods that are called Nanson method and Baldwin method (also called Total Vote Runoff or TVR). Both methods are designed to satisfy the Condorcet criterion, and allow for incomplete ballots and equal rankings. The Nanson method is based on the original work of the mathematician Edward J. Nanson in 1882.
Majority judgmentMajority judgment (MJ) is a single-winner voting system proposed in 2010 by Michel Balinski and Rida Laraki. It uses a highest median rule, i.e., a cardinal voting system that elects the candidate with the highest median rating. Unlike other voting methods, MJ guarantees that the winner between three or more candidates will be the candidate who had received an absolute majority of the highest grades given by all the voters.
Cumulative votingCumulative voting (also accumulation voting, weighted voting or multi-voting) is a multiple-winner method intended to promote more proportional representation than winner-take-all elections such as block voting or first past the post. Cumulative voting is used frequently in corporate governance, where it is mandated by some (7) U.S. states (see e.g., Minn. Stat. Sec. 302A.111 subd. 2(d).). Cumulative voting was used to elect the Illinois House of Representatives from 1870 until its repeal in 1980 and used in England and Scotland in the late 19th century to elect some school boards.
Multiwinner votingMultiwinner voting, also called multiple-winner elections or committee voting or committee elections, is an electoral system in which multiple candidates are elected. The number of elected candidates is usually fixed in advance. For example, it can be the number of seats in a country's parliament, or the required number of members in a committee. There are many scenarios in which multiwinner voting is useful. They can be broadly classified into three classes, based on the main objective in electing the committee: Excellence.
Positional votingPositional voting is a ranked voting electoral system in which the options or candidates receive points based on their rank position on each ballot and the one with the most points overall wins. The lower-ranked preference in any adjacent pair is generally of less value than the higher-ranked one. Although it may sometimes be weighted the same, it is never worth more. A valid progression of points or weightings may be chosen at will (Eurovision Song Contest) or it may form a mathematical sequence such as an arithmetic progression (Borda count), a geometric one (positional number system) or a harmonic one (Nauru/Dowdall method).
