Role of expectations and explanations in learning by teaching

The present study examined the role of preparing to teach (i.e., teaching expectancy) and actually teaching (i.e., explaining to others) on immediate and long-term learning. In Experiment 1, participants studied a base version or an enhanced version of a paper-based lesson on how the Doppler Effect works with the expectation of taking a test on the material or with the expectation of teaching the material by providing a video-recorded lecture. Results indicated that those who prepared to teach (without actually teaching) outperformed those who prepared for a test on an immediate comprehension test (i.e., a teaching expectancy effect; d = .55), regardless of the format of the lesson. In Experiment 2, participants studied while expecting to be tested or expecting to teach the material; some then actually did teach the material by providing a video-recorded lecture, whereas others received additional study time. Results indicated that those who actually taught the material outperformed those who did not teach on a delayed comprehension test (i.e., a teaching effect; d = .56), though this effect was strongest for those who also prepared to teach. Overall, these findings are consistent with the idea that preparing to teach results in short-term learning gains, whereas the act of teaching (i.e., by explaining the material to others) coupled with preparing to teach is important for long-term learning.