Students Still Learn From Watching Sped-Up Lecture Videos, Study Finds

Can students still learn effectively even if they watched sped-up lecture videos? A team of researchers found that they still do, but only "up to a point."

Remote learning due to the pandemic had many students watching recorded lecture videos for class. Many students have even developed the practice of "speed-watching" lecture videos, in that they watch them at double or faster speeds than normal, the University of California, Los Angeles (UCLA) noted in a news release.

But does this practice affect the students' comprehension of the lesson? To find out, a team of researchers conducted several experiments.

For their study, published in the journal Applied Cognitive Psychology, the researchers presented students with lecture videos that ran at different speeds and tested their comprehension immediately after as well as with a week of delay.

In one of the experiments, 231 UCLA students watched two lecture videos, one of which was about the Roman Empire while the other was about real estate appraisals, UCLA noted. The lectures ran for 13 to 15 minutes, and the students were divided into four groups that watched the videos at various speeds: normal speed, 1.5 times the normal speed, twice the normal speed and 2.5 times the normal speed.

A video shared by the university showed just how different the videos appeared to the viewers.

They were then given tests "immediately" after the viewing. The ones who watched at normal speeds got an average of 26 out of 40, while the group that watched at double the speed got 25 out of 40, which the university noted is about the same as the group that watched the videos at 1.5 speed.

On the other hand, the group that watched at 2.5 speed only got 22 out of 40. When the four groups took different tests on the same subjects a week later, the group that watched at 2.5 speed got the lowest average again at 20 out of 40 compared to the other groups.

This showed "minimal costs" of increasing the video speed by 1.5 or two times the normal speed, the researchers noted. However, "performance declined" beyond twice the speed.

"We also compared learning outcomes after watching videos once at 1x or twice at 2x speed," the researchers wrote. "There was not an advantage to watching twice at 2x speed but if participants watched the video again at 2x speed immediately before the test, compared with watching once at 1x a week before the test, comprehension improved."

According to the researchers, this showed that watching videos up to twice the speed may be an "efficient strategy," particularly if the students use the extra time for studying. However, the trends may still differ depending on factors such as video difficulty or complexity and speech rates.

"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," study lead Dillon Murphy of UCLA, said in the university news release. "Students can enhance learning if they spend the time saved on activities such as reviewing flashcards or taking practice tests."