Derek Muller, best known for creating the YouTube channel Veritasium, has a great video on the effectiveness of science videos (8 minutes), but his research may be helpful for in-class lectures in addition to online educational videos. He did his Ph.D. research on how to create films to teach science, specifically physics.
Muller found that when students watch a clear, concise video, 5 bad things happen.
Students think they know the material already.
They don't pay utmost attention.
They don't recognize that what was presented differs from what they were already thinking.
They don't learn a thing.
They get more confident in the ideas they were thinking before.
In contrast to clear, expository summaries, Derek found that videos with a dialogue about misconceptions and the correct ideas showed greater learning gains. For example, he showed a conversation between two students, where one presents a common misconception and then discusses with the other student why the misconception did not work.
Students said the dialogue video was confusing and that it took more mental effort to watch the video. But the students who viewed it learned much more than their friends watching the clear, simple video.
Therein lies the challenge for instructors in videos or in classrooms. Students learn more effectively by watching or engaging in a challenging discussion, although they may not like it or rate it highly.
Note that in this behind-the-scenes interview video (14 min), Derek says that clear, concise expository summaries are effective for experts but not for novices.
So the takeaway is to choose the right teaching style for your audience. Discuss misconceptions with novices, even if they call your lecture confusing, and save the clear explanations for experts.
Paul Simeon holds a Ph.D. in astrophysics at Stanford and is an instructional consultant at the Stanford Center for Teaching and Learning.
Want to see more from Derek Muller?
Other Teaching Talk blog posts on misconceptions and confusion: