The findings are remarkable because previous studies have suggested that 275 words per minute is the point at which comprehension starts to decline.
Students who watch videos at double speed learn just as much as those watching them at normal speed.
Theoretically, then, it is possible to learn the same amount in half the time.
The study was prompted by the fact that during the pandemic many students were forced to watch online videos rather than attend lectures in person.
Fully 85 percent of students report ‘speed-watching’ these lecture videos.
Despite doubling the speed of the video, though, students show little decline in their learning.
Mr Dillon Murphy, the study’s first author, said:
“Surprisingly, video speed had little effect on both immediate and delayed comprehension until learners exceeded twice the normal speed.”
The findings are remarkable because previous studies have suggested that 275 words per minute is the point at which comprehension starts to decline.
People typically talk at around 150 words a minute, so double speed (300 words per minute) would be beyond this limit.
However, it may be that with practice students have acquired the skill of understanding and retaining speech at higher rates.
Double time
For the study, over 200 UCLA students were split into four groups who watched a 15 minute lecture at different speeds without pausing the video or taking notes:
- Normal speed,
- 1.5 times normal speed,
- double speed,
- and 2.5 times normal speed.
Participants were given comprehension tests immediately and a week later.
The results revealed that the double-speed group scored virtually the same as the normal-speed group, both immediately after the lecture and one week later.
Pushing the playback beyond double speed, however, caused learning and comprehension to drop sharply.
Mr Murphy said:
“College students can save time and learn more efficiently by watching pre-recorded lectures at faster speeds if they use the time saved for additional studying, but they shouldn’t exceed double the normal playback speed.
While our study didn’t reveal significant drawbacks to watching lecture videos at up to double the normal speed, we caution against using this strategy to simply save time.
Students can enhance learning if they spend the time saved on activities such as reviewing flashcards or taking practice tests.”
Complex or difficult material
The researchers also experimented with various combinations of re-watching the lectures at different playback rates.
The most interesting of these combinations was when the lecture was speed-watched twice one week apart, which led to better retention than if the lecture had been watched once at normal speed.
However, listening at double speed may not be effective with more complex or difficult material.
In this study, students watched lectures on the Roman Empire and real estate appraisals.
If the subjects had been thermodynamics or immunology, the results may have been different.
Related
The study was published in the journal Applied Cognitive Psychology (Murphy et al., 2022).
