HN user
All I want to argue is that, at best, this is a slim advantage of a video over a book. So we shouldn't be saying that Khan Academy is revolutionary in any meaningful sense. It's a new medium for the same old content, and it's a medium whose advantages are pretty slim, at least for the way Khan is using video.
What's the difference between KA's videos and something written? If I don't know something, can't I just look it up on wikipedia or some other website? Or, a book?
Here's what I'm getting at: NOTHING about KA is revolutionary. Nada. You can read a book as quickly or as slowly as you like. If you don't understand something, you go back.
"Ah, but these are videos. It's an actual human speaking." Well, yeah, the recording of an actual human speaking. Problem is that there's no pedagogical theory that supports the idea that a passive recording is especially effective when it comes to learning.
People don't like being told that they have misconceptions, especially about subjects that they take themselves to be experts in. And smart people consider themselves experts about learning. But the truth is that there's a research science concerning learning, and there are some surprising findings. Further, the truth is that smart people are resentful towards this science, because it challenges their views, and that teachers are more likely to be experts in this science than anyone else.
Fact: Passive learning techniques aren't especially effective at the kinds of learning that matter most. Listening to a video is passive learning.
Important (free) reading: http://www.nap.edu/catalog.php?record_id=9853
The problem with Khan Academy is two-fold: (1) the pedagogy is lousy and (2) the delivery actually isn't that revolutionary. The ability to move at your own pace is provided by a book. To the extent that Khan's videos are easier on a person than reading, that's because they're less effective (because they're more passive).
There's a way to use the web to revolutionize education, but it's not by making material more accessible. It's by making people -- teacher, tutors and students -- more accessible to each other.