We’ve found some interesting new research which suggests the optimal video length for student engagement is six minutes or less. It’s no big surprise that students lose interest in videos that are too long; however, what’s interesting is that average engagement actually decreases as a video’s duration increases.
Philip Guo, Assistant Professor of Computer Science at the University of Rochester, spent a summer at edX analyzing online math and science courses. He found that on average, student engagement of any video maxes out at six minutes. Most students spend about three minutes viewing videos longer than 15 minutes, but will watch almost the entire video if it’s no longer than six minutes.
Studies by The Wall Street Journal published similar results; students lose interest in longer lecture videos and become distracted. If lectures are short or broken up by some kind of interaction (such as quizzes), then engagement is far higher.
The main thing instructors can take away from these studies is that it’s certainly worth thinking about how to to break instructional videos into a series of shorter clips to maximize their students' engagement.
Philip Guo’s full article is a must-read for anybody involved in the production of educational video content.