Earlier, I described a new approach to teaching that is very old: the flipped or inverted classroom. Here I’ll start describing some of the nitty-gritty details, and some of the pitfalls.
The most important thing to remember: A video lecture is NOT an ordinary lecture that has been videotaped.
A lot of folks have videotaped their lectures and put them online. These videotaped lectures have their role, but in general, they don’t work for flipped courses for two important reasons:
- A lecture is 50+ minutes with a captive audience.
- A human visual field covers 120+ degrees.
What this means is that you can talk for a long time on a topic, and you can cover the board with lots of information.
In contrast, a person watching a video on the internet has an attention span of about 5 minutes. (Be honest with yourself: How often do you sit through the entirety of a 15 minute YouTube video, and how often do you fast forward until you get to the interesting bits?) This means if you videotape a 50 minute lecture, most people will watch it for five minutes…and it is nearly impossible for someone to fast forward through the lecture to find the relevant parts.
There’s another problem: that video also covers maybe 60 degrees of the person’s visual field. This means you have considerably less space to present information. When PowerPoint first came out, most users forgot about that, and loaded slides with hundreds of words and loads of information. These days…most users still don’t understand that if a slide contains more than about 100 words, it will be unreadable.
What does this mean for math teachers? I’ve adopted the ten minute rule: If the material takes longer than 10 minutes to present, break it down into 9-minute segments, and include 1 minute at the beginning to review the material of the previous 10-minute segment.
So here’s the first step in flipping a course: breaking the entire curriculum into 10-minute segments. If you’re a gonzo mathematician like myself, you’ll do this all at once, and even for courses you have never taught like abstract algebra. But if you’re a normal, sane person who wants to stay that way, you’ll take a more sensible approach. I’ll talk about that in a future post.