Risk-limiting audit (RLA)
1. Risk-limiting tabulation audit: a post-election tabulation audit procedure for checking a sample of ballots (or voter verifiable records) that is guaranteed to have a large, pre-specified chance of correcting the reported outcome if the reported outcome is wrong (that is, if a full hand count would reveal an outcome different from the reported outcome).
Source: Election Terminology Glossary - Draft, National Institute of Standards and Technology (NIST), https://pages.nist.gov/ElectionGlossary/
2. A risk-limiting audit provides statistical assurance that election outcomes are correct by manually examining portions of paper ballots or voter-verifiable paper records.
Source: Information Technology Terminology, U.S. Election Assistance Commission, https://www.eac.gov/documents/2017/09/21/information-technology-terminology-security
3. A risk-limiting audit is a type of post-election audit, during which a random sample of ballots is selected and the selections on the ballots are compared to the electronic “cast vote record” inside a voting machine. In a decisive contest, a small sample of ballots can be audited, while a close race will require a comparatively larger sample.
Source: America’s Voting Machines at Risk, Brennan Center for Justice, https://www.brennancenter.org/sites/default/files/2019-08/Report_Americas_Voting_Machines_At_Risk.pdf
4. A procedure for checking a sample of ballots (or voter verifiable records) that is guaranteed to have a large, pre-specified chance of correcting the reported outcome if the reported outcome is wrong (that is, if a full hand count would reveal an outcome different from the reported outcome).
Source: Pilot Implementation Study of Risk-Limiting Audit Methods in the State of Rhode Island, RLA Working Group,https://www.brennancenter.org/sites/default/files/2019-09/Report-RI-Design-FINAL-WEB4.pdf
5. A post-election audit that provides strong statistical evidence that the election outcome is correct and has a high probability of correcting a wrong outcome.