Usability of voting systems: baseline data for paper, punch cards, and lever machines

In the United States, computer-based voting machines are rapidly replacing other older technologies. While there is potential for this to be a usability improvement, particularly in terms of accessibility, the only way it is possible to know if usability has improved is to have baseline data on the usability of traditional technologies. We report an experiment assessing the usability of punch cards, lever machines, and two forms of paper ballot. There were no differences in ballot completion time between the four methods, but there were substantial effects on error rate, with the paper ballots superior to the other methods as well as an interaction with age of voters. Subjective usability was assessed with the System Usability Scale and showed a slight advantage for bubble-style paper ballots. Overall, paper ballots were found to be particularly usable, which raises important technological and policy issues.