A mock paper that kept repeating itself
Year 11 student Maya lost fourteen marks on her second maths mock. The losses were not spread across the paper; they clustered in three places: expanding brackets with negatives, rearranging formulae, and rounding at the wrong stage. She had corrected the first mock in red pen, yet the same errors returned three weeks later. This is the problem duffspin is designed to interrupt: not a lack of effort, but a missing review loop that turns a corrected paper into a durable cue.
Why red-pen correction often fails
The cause is usually not laziness. Students treat correction as a record of what went wrong rather than a set of prompts to retrieve later. They reread the worked solution, nod at the step they missed, and move on. Because they never have to produce the step from memory under time pressure, the correction stays fragile. The fix is to convert each duff into a spin: a short, testable rule that can be applied when the examiner is not sitting beside them.
The duffspin routine, step by step
The version I recommend takes about eight minutes per paper and uses three moves.
- Name the duff. Write the exact error, not a vague label. Instead of “careless”, write “dropped the negative sign when expanding -2(x – 3)”.
- Spin it into a cue. Turn the error into a question you can ask in the exam. For that example, the cue might be: “When a bracket is multiplied by a negative, where does the sign change?”
- Re-test cold. After twenty-four hours, answer two fresh questions that trigger the same cue, without notes. If you miss either, rewrite the cue, not the whole page.
For a worked example of this routine in a tutoring context, see duffspin. The point is not to produce prettier notes; it is to make the correction memorable enough to fire in an exam.
What changed after four weeks
Maya used duffspin on three papers and kept a simple table: duff, spin cue, cold-test result. Her lost marks in the same three topics fell from fourteen to five. The improvement came from making errors into triggers, not confessions. Teachers can use the same routine at the end of a feedback lesson: one minute for students to write one duff and one spin. A mark scheme tells you what went wrong; duffspin tells you what to practise next.