Effectiveness, efficiency, and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment. Usability in the context of voting refers to voters being able to cast valid votes as they intended quickly, without errors, and with confidence that their contest selections were recorded correctly. It also refers to the usability of the setup and operation of voting equipment in the polling place.

Source: Election Terminology Glossary - Draft, National Institute of Standards and Technology (NIST),; Glossary of terms database, U.S. Election Assistance Commission,