Audits require human examination of voter-marked paper ballots — the ground truth of the election. Voter-marked paper ballots may be marked by hand or by ballot marking device. Audits cannot rely on scanned images or machine interpretations of the ballots to accurately reflect voter intent.
- Paper ballots, whether marked by hand or by a ballot marking device, are easy for both voters and auditors to read or verify. They are durable and easy to handle during an audit.
- Ballots are designed to reduce ambiguity and to reliably reflect the intent of the voters. Care is taken to urge voters to confirm that the paper ballot reflects their votes as intended, whether they mark their ballots by hand or using a ballot marking device.
- The audit treats as authoritative only marks on paper that the voter could verify. It does not rely upon the accuracy of barcodes (including QR codes), images of ballots, electronically transmitted ballots, remade ballots or other unverified products of the election system.
- The auditors do not know the machine interpretations or counts of the ballots they are auditing.
- Human auditors interpret voter intent as recorded on the paper ballots, although technology may be used to assist and augment audits.Since audits help ensure the “software independence” of the election results, care is taken to ensure and document software independence of the audit itself: no undetected change or error in any technology system used to assist with the audit will be able to cause an undetected change in the audit outcome. In no case is the vote-tabulating system a trusted component of the audit process. In particular, the ballot manifest must be created or verified independent of the voting system.
(Adapted from Principles and Best Practices for Post-Election Tabulation Audits, 2018)