A few months ago I blogged about my summer 2013 research on optimalvideo length for studentengagement.Recently Juho Kim, a Ph.D. student at MIT,Rob Rubin, the VP of Engineering at edX, and I extended that work andpublished the following paper at the new ACM Learning atScale conference:
Philip J. Guo, Juho Kim, Rob Rubin. How Video Production AffectsStudent Engagement: An Empirical Study of MOOCVideos.ACM Conference on Learning at Scale, March 2014.
[BibTeXcitation]
This blog post summarizes our paper.
Videos are central to the student learning experience in many kinds of MOOCs.
The above figure shows four main kinds of videos on the edX platform:a.) a recorded classroom lecture, b.) an instructor's talking head, c.)a Khan-style digital tablet drawing (popularized by Khan Academy), andd.) a PowerPoint slideshow.
Research Question: How does video production affect studentengagement in MOOCs?
Methodology: We measured engagement by how long students watchedeach video and also whether they attempted to answer post-videoassessment problems.
We took all 862 videos from four edX courses offered in Fall 2012 andhand-classified each one based on its type (e.g., traditional lecture,problem-solving tutorial) and production style (e.g., PowerPointslides, Khan-style tablet drawing, talking head). We automaticallyextracted other features such as length and speaking rate (words perminute). We then mined the edX server logs to obtain over 6.9 millionvideo watching sessions from almost 128,000 students.
To our knowledge, this is the largest-scale study of video engagement todate.
Here are our seven main findings and corresponding recommendations forcreators of online educational videos:
1. Shorter videos are much more engaging. Engagement drops sharplyafter 6 minutes.
Recommendation: Invest heavily in pre-production lesson planning tosegment videos into chunks shorter than 6 minutes. This is the mostsignificant recommendation!
2. Videos that intersperse an instructor's talking head withPowerPoint slides are more engaging than showing only slides.
Recommendation: Invest in post-production editing to display theinstructor's head at opportune times in the video. But don't gooverboard because sudden transitions can be jarring. Picture-in-picturemight also work well.
3. Videos produced with a more personal feel could be more engagingthan high-fidelity studio recordings.
Recommendation: Try filming in an informal setting such as an officeto emulate a one-on-one office hours experience. It might not benecessary to invest in big-budget studio productions.
4. Khan-style tablet drawing tutorials are more engaging thanPowerPoint slides or code screencasts.
Recommendation: Introduce motion and continuous visual flow intotutorials, along with extemporaneous speaking so that students canfollow along with the instructor's thought process.
5. Even high-quality prerecorded classroom lectures are not asengaging when chopped up into short segments for a MOOC.
Recommendation: If instructors insist on recording traditionalclassroom lectures, they should still plan lectures with the MOOC formatin mind and work closely with instructional designers who haveexperience in online education.
6. Videos where instructors speak fairly fast and with high enthusiasmare more engaging.
Recommendation: Coach instructors to bring out their enthusiasm andreassure them that they do not need to purposely slow down. Students canalways pause the video if they want a break.
7. Students engage differently with lecture and tutorial videos.
Recommendation: For lectures, focus more on the first-time watchingexperience. For tutorials, add more support for rewatching and skimming,such as inserting subgoallabels inlarge fonts throughout the video.
Read the fullpaperfor details.
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