In good news for those who like racing through audiobooks at double speed, a new study from a team at UCLA has found learning and knowledge retention is not negatively effected when students watch recorded lectures at faster playback speeds. However, comprehension was found to suffer when playback reached 2.5 times normal speed.
Over the last decade digital resources in education have allowed students a number of new ways to study. In particular, the prevalence of access to recorded lectures has often led to students manipulating playback speeds of videos in order to cram more information into shorter study periods. But does speeding up content help or hinder one's comprehension of the material?
A variety of studies have recently explored how playback speeds affect learning and comprehension and the results so far have been decidedly mixed, with some research suggesting speeding up lecture videos can lead to beneficial learning outcomes, while others indicate the practice could hinder comprehension.
This new UCLA study, while far from definitive, adds weight to the argument that faster playback of study materials is at least as effective as normal playback speeds. Just as long as you don’t play those materials too fast.
The study recruited 231 students into four different playback speed groups (normal speed, 1.5X, 2X and 2.5X). Each group watched a pair of short lecture videos and then immediately completed a 40-question comprehension test.
Little difference was found between the normal playback speed group and the 1.5 times or double speed groups. They all performed similarly on the tests, but the group watching videos at 2.5 times normal speed displayed minor learning impairments. A second test a week later saw similar results, suggesting neither short- or long-term comprehension was negatively affected by watching videos at faster playback speeds.
“Surprisingly, video speed had little effect on both immediate and delayed comprehension until learners exceeded twice the normal speed,” explains lead author Dillon Murphy.
An interesting extra experiment in the study looked at the effects of watching lecture videos twice at double speed compared to once at normal speed. No difference was detected in test results between these two groups, unless the second fast viewing took place a week later, immediately before the exam.
Those who watched the lecture videos at double speed for the second time right before the exam one week later performed slightly better than those who viewed the video a single time at normal speed the week prior.
“… superior exam performance only occurred when the twice at 2x speed group's second viewing occurred shortly before the exam,” the researchers write in the new study. “Thus, learners may be able to strategically distribute their study time to increase performance by watching lecture videos twice at 2x speed but watching for the second time shortly before an exam.”
The researchers are cautious to note faster playback speeds may not be useful when trying to study more complex topics. Faster playback speeds could also be deleterious to comprehension when watching lectures containing lots of visual material. The lecture topics used in the study were ancient Roman history and real estate appraisals.
Murphy says students should be careful about how they deploy faster playback in terms of finding optimal study strategies. If students choose to speed up lecture playback, Murphy says, they should use the time saved for additional learning.
“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,” Murphy says. “Students can enhance learning if they spend the time saved on activities such as reviewing flashcards or taking practice tests.”
The new study was published in the journal Applied Cognitive Psychology.
Source: UCLA
