Voter Verification of Ballot Marking Device Ballots Is a Two-Part Question: Can They? Mostly,They Can. Do They? Mostly,They Don't

The question of whether or not voters actually verify ballots produced by ballot marking devices (BMDs) is presently the subject of some controversy. Recent studies (e.g., Bernhard et al. 2020) suggest the verification rate is low. It is unclear if this is because voters cannot do this accurately or whether it is because voters simply choose not to attempt verification in the first place. In order to answer this question, we conducted an experiment in which 108 participants participated in a mock election where the BMD displayed the voters' true choices, but then changed a subset of those choices on the printed ballot. The design of the printed ballot, its length, the number and location of changes that were made to the ballot, and the instructions provided to the voters were manipulated as part of the experiment. Results indicated that of those voters who chose to examine the printed ballot, 76% detected anomalies, indicating that voters can reliably detect errors on their ballot if they simply review it. This suggests that administrative remedies, rather than attempts to alter fundamental human perceptual capabilities, could be employed to encourage voters to check their ballots, which could prove as an effective countermeasure.