Kim, J., Guo, P. J., Seaton, D. T., Mitros, P., Gajos, K. Z., & Miller, R. C. (2014, March). Understanding in-video dropouts and interaction peaks inonline lecture videos. In Proceedings of the first ACM conference on Learning@ scale conference (pp. 31-40).
https://doi.org/10.1145/2556325.2566237
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Empirical study of drop-out rates and viewing statistics in a large number of edX course videos.
Peaks in viewing numbers – indicating rewinding and re-watching – occur around visual transitions. Students go back to a slide that’s suddenly gone and use the transitions as visual ‘bookmarks’ to re-watch or rewind to a particular explanation or section of the video.
Therefore, avoid taking away diagrams and other visual aides too soon and/or abruptly. Include clear visual anchors (e.g. title cards) at the start of sections, provide timestamps, or cut up longer videos into shorter ones.