Three Eras of Voting Methods
There are three kinds of voting methods— allocative, comparative, and evaluative—based on the expression form and constraint. Allocative methods give each voter a fixed amount of “vote” (continuously divisible or as discrete tokens) to allocate among candidates. Comparative methods allow voters only to show preference between pairs of candidates; generally, this is done by ranking them. Evaluative methods have voters rate candidates independently on a scale (numeric or graded). There are also hybrids, e.g. multi-stage voting methods that combine voting methods of different categories.