Learning in double time: The effect of lecture video speed on immediate and delayed comprehension
Researchers examined how lecture video playback speed affects student learning by having undergraduates watch recorded lectures at normal speed (1x), faster speeds (1.5x, 2x, 2.5x), or by watching videos more than once at increased speed. Students completed comprehension tests immediately after viewing and again one week later. The study focused on whether faster playback harms understanding or long-term retention, a common concern among instructors using recorded lectures.