Psychologists from the University of Illinois have shown that the effectiveness of learning does not decrease with increasing video playback speed, but it can increase the load on the person. The study was published in: Journal of Experimental Psychology: Applied.
The scientists created a series of instructional videos and tested with volunteers how well they absorbed the information in the videos as the speed increased. Doubling the speed did not reduce the effectiveness of the training, but even a small acceleration by 1.5 times significantly increased the subjective load on the audience.
In the second phase, the researchers showed participants a more selectively time-lapse video that played during pauses, slow speech, or pronunciation of unimportant information. These videos were found to be as time-effective as 150% fast videos, but participants rated them as more comfortable.
In the last decade, videos have become popular teaching tools. Many sites offer faster video playback. While previous research has shown that moderate speed may not interfere with learning, few have tested a 200% increase in speed. It was also unknown to what extent users found the speed boost tedious and/or unpleasant, even if the acceleration did not hinder learning.