This week, I’m helping to facilitate a professional development workshop to train faculty to teach online. This workshop is offered twice a year and the participants always have a lot questions about the best ways to teach online. This group is particularly inquisitive and really interested in what research says about online learning. Yesterday, we were introducing different tools for creating record lectures for use in online classes when one of the participants asked, “How long should a recorded lecture be?” Since a face-to-face classes are usually scheduled to last an hour (or longer), the faculty member wondered, shouldn’t online lectures be a comparable length?
The simple answer is “No.” If the goal is for students to watch the entire video, instructors need to be strategic with how they create videos. Wistia, a streaming service for business videos, examined data from millions of views of their online lessons. Across the videos they analyzed, the researchers found that as the size increased, the percentage of viewers who watched the entire video decreased. Looking at the graph below, when a video was less than two minutes long, viewers on average only watched about 65% of it. If a video was 60 minutes long (or more), viewers watched less than 30% of the video.