Explain the material to someone else — real or imagined

Teaching forces you to process at the deepest level: organizing information coherently, identifying gaps, and translating to another person’s perspective.

Why it works

Teaching activates multiple deep-processing demands simultaneously: you must retrieve the information, organize it coherently (which reveals structural understanding), generate examples accessible to a non-expert, and monitor whether the explanation is making sense — all of which require semantic processing far deeper than reading or re-reading. The Protégé Effect (documented by Chase et al.) shows that even preparing to teach someone else improves learning before any actual teaching occurs, suggesting the encoding benefit is in the anticipation of explanation.

How to do it

1. After studying, explain the material aloud as if to someone who has no background in it.
2. When you cannot explain a step clearly, mark it as a genuine gap and return to the source.
3. Use the Feynman technique: explain in the simplest language possible, then identify every word that requires background knowledge the imagined listener doesn’t have.
4. Record or write the explanation so you can review where it broke down.

Evidence

The Protégé Effect has been documented in learning science: students who expected to teach material to others learned it more deeply than those who expected to take a test (Nestojko et al., 2014). The learning-by-teaching finding is supported by multiple studies across educational levels. Chase et al. (2009) demonstrated the Protégé Effect directly with teachable agents, showing learners invest more effort when working on behalf of someone they are teaching than for themselves. (observational)

The effect is strongest when the learner believes they will actually teach and when the teaching is genuinely prepared (not just announced); ceremonial "pretending to teach" may not activate the mechanism fully.

Sources

• Nestojko et al. (2014), Expecting to teach enhances learning and organization of knowledge in free recall of text passages, Memory & Cognition
• Nestojko, J. F., Bui, D. C., Kornell, N., & Bjork, E. L. (2014). Expecting to teach enhances learning and organization of knowledge in free recall of text passages. Memory & Cognition, 42(7), 1038–1048.
• Chase, C. C., Chin, D. B., Oppezzo, M. A., & Schwartz, D. L. (2009). Teachable agents and the protégé effect: Increasing the effort towards learning. Journal of Science Education and Technology, 18(4), 334–352.

Common mistake

Using vague summaries ("it’s basically about X") instead of genuinely working through the explanation step-by-step — the gaps only surface when you try to produce a complete, sequential account.