Asking questions that reveal what students actually think

Most classroom questions are checks that something was said, not checks that something was understood. "What is the formula for the area of a circle?" is answered correctly by a student who cannot use it, cannot recognise when it applies, and thinks radius means the distance across. The answer was right and you learned nothing.

Design the wrong answers first

A diagnostic question is one where each wrong answer means something specific. Before writing the options, list the misconceptions you expect, then make each one available as an option. If a third of the group picks the option that corresponds to "confuses radius with diameter", you now know precisely what to teach next, and you know it in thirty seconds.

This is why a multiple-choice question with lazy distractors is worse than no question. Options that are obviously absurd let a confused student answer correctly by elimination, and the confusion survives the check intact.

Three question types that are hard to fake

• "Which of these is not…" Recognition of a non-example needs a real boundary in the concept. Students who have memorised a definition frequently cannot do it.
• "Two students disagree…" Present both positions and ask which is right and why. It legitimises the wrong view, so students who hold it will actually reveal that they do.
• "Would the answer change if…" Vary one condition. This separates the student who followed a procedure from the one who understands what the procedure depends on.

Wait, then hear from everyone

Two things ruin an otherwise good question. The first is answering it yourself after three seconds of silence. Three seconds is not enough time to think, and doing it consistently teaches the class that waiting is the winning strategy. The second is taking one answer from a volunteer. A single confident student tells you about that student.

Where to use them

You do not need many. Two genuinely diagnostic questions per session, at the points where you most suspect a misconception hides, are worth more than twenty checks that everyone passes.

Sources

• What Works Clearinghouse — Educator Practice Guides (US Dept. of Education)
• UNICEF — Education