Active Recall Beats Re-Reading

Most students highlight textbooks and re-read notes. Research by Jeffrey Karpicke at Purdue University found that students who practiced active recall — testing themselves instead of re-reading — retained far more a week later. The struggle to retrieve is what builds lasting memory.

Active recall works because it forces your brain to rebuild information from scratch. Passively seeing something feels easy, but easy does not build durable memories. If you can close the book and explain it, you know it. If you cannot, you only recognize it.