After studying, close the book and test yourself — don’t just reread it

There’s no cost involved, and no extra time is needed. Use the time you’d otherwise spend rereading to write down or answer questions from memory instead. The difficulty lies in how uncomfortable it feels to confront what you’ve forgotten right away, compared to the relative ease of rereading.

A meta-analysis of 222 independent studies and 48478 students: classroom quizzes raised academic scores, with a moderate effect size (g = 0.499). Effect size depends on several conditions: what study method the control group used, whether quiz format matched the final exam, whether materials matched, and whether corrective feedback was given. Also how many times the quiz was repeated, where and when it was given, how long the intervention lasted, and what experimental design was used. Another review that rated ten common learning methods one by one put "practice testing" and "spaced practice" in the highest band (high utility). The reason is that they work across ages and abilities, and have been checked across many assessment formats and real education settings.

Yang C, Luo L, Vadillo MA, Yu R, Shanks DR (2021). Testing (quizzing) boosts classroom learning: A systematic and meta-analytic review. Psychological Bulletin, 147(4), 399–435. https://doi.org/10.1037/bul0000309；Dunlosky J, Rawson KA, Marsh EJ, Nathan MJ, Willingham DT (2013). Improving Students' Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology. Psychological Science in the Public Interest, 14(1), 4–58. https://doi.org/10.1177/1529100612453266

Self-testing is meant to force information out of your memory, not to assign grades. The recommended approach is to write down key points from memory after reading a section, then check them against the text. Providing corrective feedback further boosts effectiveness, so it’s important to carefully review why each answer was incorrect. The “large” magnitude of benefit mentioned here is determined by both the effect size and the overall rating. Since these studies measured academic outcomes rather than time saved, they weren’t evaluated against time‑saving thresholds. Self-testing and the method described in item 15 — spreading the same amount of study time across several days — are the two highest‑rated strategies identified in the same review; using them together yields the best results.