Turn your notes into practice questions

Rereading feels productive, but a large review of ten study techniques rated rereading and highlighting low utility. Testing yourself and spacing your study were the two rated high (Dunlosky et al. 2013).

The 20 minute method

1. Pick one page of notes. Cover it.
2. Write 5 questions a teacher could ask. Use "why" and "how" for at least two (asking why a fact is true is elaborative interrogation).
3. Answer each from memory, in writing. Do not peek.
4. Uncover the notes and check. Mark each answer right, partly or wrong. Testing with feedback has a larger benefit than testing without it (Adesope et al. 2017).
5. Rewrite the wrong ones as new questions for tomorrow.

Why writing the answer matters

Producing an answer beats reading it, and the gap grows after a day (Bertsch et al. 2007). The benefit is mostly for the exact item you generated, so write questions that cover the whole page.

Math and problem sets

For math, spacing still helps but the benefit of plain recall is not clearly reliable (Murray et al. 2025; the effect was small and its confidence interval included zero). Work full problems, mix problem types, and check your steps.