The class that set its own test

A teacher asked each student to write three exam questions on a topic and to supply the answers. The exercise took one lesson and replaced two lessons of revision.

Writing a question turns out to be a harder task than answering one, and the difficulty is informative. To write a usable question a student has to decide what the important idea is, work out what a wrong answer would look like, and check that the question has one defensible answer. Each of those steps requires knowing the material from the outside, which is exactly the position an examiner is in and exactly the position a student revising from notes never occupies.

The wrong answers were the most useful part. Asked to invent three plausible distractors, students produced the misunderstandings they themselves had held a week earlier, and seeing them written down as options made the distinction explicit. The teacher collected the best of these and used them in the real test, which had the side effect of making the distractors sharper than anything she would have written alone.

There are two failure modes worth knowing. Students asked to write questions without a worked answer produce vague ones, because the answer is where the difficulty surfaces. And students allowed to choose any topic write about what they already know, so the topic has to be assigned. The deeper reason the exercise works is that it changes the direction of attention. Reading notes is a search for recognition. Writing a question is a search for what would be hard, and the second search finds the gaps that the first one is designed to glide over.