As I’ve mentioned once or twice here before, I’m writing a feature piece for City Journal on the Khan Academy. These online video lectures cover various math and science topics, and the math problem sets on the site encourage individually-paced, sequential-learning to mastery.
Anyway, the videos are interesting, but they’ve also sparked some interesting criticism. One critique is from Derek Muller, who runs Veritasium, a company which also makes science videos. He did his dissertation on how and whether students can learn by watching physics videos. He discovered something fascinating. If you pre-test people on a physics topic, they’ll likely do quite poorly. Then you show them a video on the topic, explaining it in a straightforward fashion. Then you test them again. You’d think scores would go up, right?
But they don’t. Or they did by about 0.2 points on a 1-26 scale. In other words, there wasn’t any greater comprehension. But people rated the videos as clear and compelling. They also became more convinced that their wrong answers were right.
So that’s a bit of a problem. It turns out that, with the sciences, we have our own conceptions about how many things work, because of, well, our own lying eyes. If I throw a ball in the air, and it travels up, it seems clear that some upward force is acting on it. Except there isn’t once it leaves my hand. The force acting on it is gravity, which is pushing down. So first, you have to explain why the viewer’s thinking is wrong. Then you explain the correct answer.
Net result of explaining the error, then correcting it? Muller found that comprehension close to doubled. But people didn’t really like the videos as well. They didn’t find them clear and compelling. This is one of the fascinating quirks of human nature. Even when it helps us learn, we hate to be confronted with our errors. It’s why Dale Carnegie preached against doing it. We really, really hate to be wrong. Now, to be sure, there are semi-pleasant ways to be told you’re wrong (some Veritasium videos do a version of “Jaywalking” — when Jay Leno would walk down the street asking questions and people would give him stupid answers). But either way, it is through this extra mental effort that our brains actually grow. So why can’t we appreciate it?
(Photo courtesy flickr user jervetson)