Whether the election selects a single officeholder or fills multiple seats in a council or legislature.
Single-winner
Produces one winner, such as a president, mayor, or district representative.
Multi-winner
Produces several winners, as in parliaments, councils, or corporate boards.
Both
The method can be used for either a single winner or multiple seats, depending on the context.
The way voters are asked to express their preferences on the ballot.
Single-choice
Voters mark only one candidate or party.
Multi-choice
Voters may select more than one option, as in block voting or approval systems.
Ranked
Voters list candidates in order of preference: first, second, third, and so on.
Scored
Voters assign numerical ratings, such as from 0 to 5 or 0 to 10.
Approval
Voters mark every candidate they find acceptable; all approvals count equally.
List
Voters choose a party list, or sometimes both a party and a preferred candidate within that list.
Whether the rules ensure the winner commands support from more than half the voters.
Yes
The winner must secure over 50% of votes or effective support, as in two-round or ranked-choice elections.
No
A candidate may win with less than half the vote, as in first-past-the-post, approval voting, or proportional lists.
How closely the final seat distribution reflects the overall share of votes.
Low
Seat shares can be heavily distorted—for example, 40% of votes may yield 60% of seats under first-past-the-post.
Moderate
Results adjust somewhat toward fairness, but are not fully proportional, as in limited vote or parallel systems.
High
Seat shares mirror vote shares closely, as in single transferable vote or party-list proportional representation.
The level of effort required from voters to express their preferences accurately.
Low
Marking a single or multiple ‘X’s on the ballot or marking approvals and disapprovals.
Moderate
Ranking or scoring requires more thought about candidate order or numerical values.
High
Detailed rankings or scores for many candidates, such as in large multi-seat ranked-choice elections.
The administrative difficulty of counting votes and verifying results.
Simple
Counting straightforward marks and declaring the highest total as winner.
Moderate
Requires formulas or multiple rounds, as in approval, cumulative, or two-round elections.
Complex
Involves iterative transfers, quotas, or head-to-head matrices, as in ranked-choice, Condorcet, or dual member proportional systems.
How the system treats ballots with mistakes, ambiguities, or incomplete preferences.
Strict
A ballot is spoiled by overvotes or invalid marks, as in first-past-the-post, block voting, or two-round elections.
Moderate
Some errors are tolerated, but ballots may truncate or exhaust early, as in ranked-choice or single transferable vote.
Lenient
Most partial or ambiguous ballots still count, as in approval, score, Condorcet, or party-list systems.
The chance that similar candidates split the vote and change the outcome.
High
Frequent under first-past-the-post or block voting.
Moderate
Reduced but still possible in systems like two-round or ranked-choice.
Low
Largely eliminated in approval, score, or proportional systems.
How strongly voters feel pushed to vote insincerely to avoid worse outcomes.
High
Common, as in lesser-evil voting under first-past-the-post.
Moderate
Sometimes advantageous in two-round or ranked-choice systems.
Low
Voters can usually vote sincerely in approval, score, or proportional systems.