Qualtrics is a widely used web service for surveys. It’s got plenty of useful features, one of which is the ability to include JavaScript. Jackson Walters has very kindly put up full instructions of how this can be used to track the respondents’ mouse in a particular question, following up a post on Stack Overflow. If you ever looked for mouse tracking in a self-administered web survey, look no further (assuming that you or your institute has a subscription with Qualtrics, of course).