Cardinal voting refers to any electoral system which allows the voter to give each candidate an independent evaluation, typically a rating or grade. These are also referred to as "rated" (ratings ballot), "evaluative", "graded", or "absolute" voting systems. Cardinal methods (based on cardinal utility) and ordinal methods (based on ordinal utility) are two main categories of modern voting systems, along with plurality voting.
There are several voting systems that allow independent ratings of each candidate. For example:
Approval voting (AV) is the simplest possible method, which allows only the two grades (0, 1): "approved" or "unapproved".
Evaluative voting (EV) or combined approval voting (CAV) uses 3 grades (−1, 0, +1): "against", "abstain", or "for".
Score voting or range voting, in which ratings are numerical and the candidate with the highest average (or total) rating wins.
Score voting uses a discrete integer scale, typically from 0 to 5 or 0 to 9.
Range voting uses a continuous scale from 0 to 1.
Highest median rules, which elect the candidate with the highest median grade. The various highest median rules differ in their tie-breaking methods. The majority judgment, in which the grades are associated to expressions (such as "Excellent", to "Poor"), is the most common example as it is the first such rule that has been studied, but other rules have since been proposed, e.g. the typical judgment or the usual judgment.
STAR voting, in which scores are from 0 to 5, and the most-preferred of the top-two highest-scoring candidates wins.
Majority Approval Voting, a scored variant of Bucklin voting, typically using letter grades (such as "A" through "F").
3-2-1 voting, in which voters rate each candidate "Good", "OK", or "Bad", and there are three automatic elimination steps to tally them: first step selects the three candidates with the most "Good" ratings, second the two with the least "Bad", and out of these the one preferred by the majority wins.