Audit Election Results

Election experts agree that a post-election audit is needed to verify electronic vote counts. Three factors are particularly important when designing an audit: 

  1. The audit must investigate the accuracy of the results (not just spot-check equipment).
  2. The audit must compare paper and digital records.
  3. The public must witness the procedure.
 CREDIT:  Liz West .

CREDIT: Liz West.


A Way to Limit Risk

In a typical audit, a fixed percentage of voting districts or voting machines are checked. Choosing them at random is crucial. If discrepancies are found between the manual and electronic counts, the audit escalates to look at a greater percentage.

Interpretation of discrepancies and how to handle them can be subjective, making it important to agree upon rules and procedures in advance.

The flaw with this system is that it might miss fraud entirely if it isn’t looking in the right place. To avoid this error, a new technique is emerging as the best practice: risk-limiting audits, where a set of random ballots are pulled and compared to their digital records.

According to Verified Voting

Risk-limiting post-election audits are designed to minimize the size of the audit when the outcome is correct, while with very high probability correcting the outcome, if it is incorrect, by counting all the ballots. The audit continues until there is sufficiently strong statistical evidence that the apparent outcome is right, or until all the ballots have been manually counted. There are several factors that determine the size of the audit. Two are the closeness of the race being audited and the total number of ballots cast in that race.

Next-generation voting systems should facilitate risk-limiting audits by making it easy for election officials to pull a truly random set of paper ballots for comparison with voting machine results.

Learn More

A Gentle Introduction to Risk-limiting Audits,” Mark Lindeman and Philip B. Stark, Security & Privacy, March 2012.

Risk-Limiting Post-Election Audits: Why and How,” Risk-Limiting Audits Working Group, October 2012.

Best Practices: Risk-Limiting Audits,”

Enabling More Meaningful Post-Election Investigations,” Arel Cordero, University of California at Berkeley, December 2010.


Election Audit Laws & Resources

Verified Voting

Verified Voting keeps track of audit quality across the United States. Check out their database for information on the law in your state.

Citizens for Election Integrity Minnesota

Citizens for Election Integrity Minnesota also provides a very detailed and searchable database of election audit laws across the country.

The researchers behind have compiled a comprehensive set of principles and best practices for conducting post-election audits. 

National Conference of State Legislatures

NCSL has a page of frequently asked questions about post-election audits, as well as case studies and other resources on conducting audits.