When To Ask Closed-Ended Questions
In quantitative usability studies, where you are measuring time on task and error rates, and you need to compare results among usersIn surveys where you expect many (1000+) respondentsWhen collecting data that must be measured carefully over time, for example with repeated (identical) research effortsWhen the set of possible answers is strictly limited for some reasonAfter you have done enough qualitative research that you have excellent multiple-choice questions that cover most of the cases
