What makes a good question

For real-time formative assessment the instructor must be able to quickly understand student misconceptions from their InkSurvey submissions.

Multiple sentences are difficult for the instructor to process quickly so when using text responses a one sentence answer to an open-format question is best.

Better yet, construct the open-format question so that it can be answered with an equation, figure, graph, or sketch rather than text. It is much easier and takes less time for you to process this graphical type of information.