By Christian Jarrett

Given a passage of text to study, many students repeatedly re-read it in the hope the information will eventually stick. Psychology research has shown the futility of this approach. Re-reading is a poor strategy, it’s too passive and it leads the mind to wander. Much better to test yourself on what you read, or explain it to yourself or someone else. Now a paper in Experimental Psychology suggests the same is true of lecture videos – immediately re-watching them doesn’t lead to any greater learning.

Leonardo Martin and his team asked 72 participants to watch two lecture videos, both around 10 minutes long. One was a live recording of a lecture about sanitation in the middle ages; the other consisted of voice over slides and was about problem solving. Some students watched the sanitation video first, the others watched the problem solving video first. Also, all the students watched one of the videos (either the sanitation one or the problem-solving one) just once before being tested on it, whereas they watched the other video twice in succession before being tested on it (nine multiple-choice questions in each case). Finally, while they were watching the videos, the students answered a few prompts about whether they were mind wandering or not.

If immediately re-watching a lecture video helps improve learning then the students ought to have performed better at the test that followed the video they watched twice. But this wasn’t the case – they averaged 79 per cent accuracy in the test about the video they watched once, compared with 76 per cent accuracy in the test that followed the video they watched twice (a statistically non-significant difference). The students also mind wandered more during the repeat viewing than when watching either of the lectures for the first time.

One important caveat is that this research was specifically about the effects of immediately re-watching a lecture video (“massed re-watching”, as the researchers put it). Re-watching a video after a sufficient delay could be more effective (akin to a form of distributed practice), although testing yourself is probably still the more favourable strategy.

“Re-watching a video lecture does not encourage individuals to build a richer representation of the content,” the researchers concluded, “thus leading to a more passive mode of viewing that puts little demands on attentional control, ultimately leading to more mind wandering.”

—Re-watching lectures as a study strategy and its effect on mind wandering

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest