View source for Independence of the least/most preferred

Independence of the least/most preferred (ILMP) is satisfied when:

 ILP: by adding a vote where candidate X has the '''worst''' possible rating (or rank), then that vote doesn't '''increase''' the winning chance of X.

and

 IMP: by adding a vote where candidate X has the '''best''' possible rating (or rank), then that vote doesn't '''decrease''' the winning chance of X.

This criterion must apply regardless of how the other candidates are rated.

Meeting these criterion favors the use of intermediate ratings (if present in the voting system), reducing strategies such as [[Tactical_voting#Definitions|min-maxing]]. Specifically, IMP avoids rating minimization, while ILP avoids rating maximization, and it's better.

Douglas Woodall's terms for these criteria are [[Mono-add-top|mono-add-top]] for IMP and [[Monotonicity#Woodall's_monotonicity_criteria|mono-remove-bottom]] for ILP.

[[Category:Voting system criteria]]