Question Writer Tracker Manual/Controlling and Monitoring Access/Single Use Tokens
Single Use Tokens
You can create tokens for quizzes so that they can be taken one time only. The token is available as a URL - give the URL to a user and he will be able to use it once, and once only!
This is useful if you want to sell access to quizzes you've created or you think users might be peeking at feedback answers ahead of submitting their own answers.