Here is an article attacking the Khan Academy (and a Khan response). Here is another, somewhat deeper critique. The upshot of both of these articles is the same: Khan isn’t a very good teacher.
What sour grapes! Not that this is the point, but find his videos quite good. Of course they aren’t perfect, but there is something extremely important going on here: Khan is a good teacher and he is getting better. Here are some quotes.
From a Khan employee:
Persistent misconception: “…we suggest that Khan Academy desperately needs voices of teaching experience. Khan could tap into any number of existing networks…”
Truth: We have four ex-teachers as full-time employees. We have two high school math teachers as consultants. One Harvard Doctoral candidate in Education and one post-doc in neuroscience at Stanford are in residence. One UPenn Professor is also likely to begin a sabbatical with us. We have a 3 person team dedicated to working with and getting feedback from our 50 pilot classrooms and the 15,000 teachers actively using KA in classrooms.
Persistent misconception: “…it certainly requires more than just “two minutes of research on Google,” which is how Khan describes his own pre-lesson routine.”
Truth: Go read Sal’s AMA response (includes the sentence “When I did organic chemistry, I spent 2 weeks immersing myself in the subject before making the first video”) before taking one of these “two minute” snipped quotes at face value: http://www.reddit.com/r/IAmA/comments/ntsco/i_am_salman_khan…. I’ve seen Sal’s face light up when he gets an unwieldy new shipment of textbooks to start studying in preparation for his videos. Does he dive right into some videos? Absolutely. Is claiming that his “pre-lesson routine” can always be dismissed as two minutes of Googling disingenuous and patently false? Absolutely.
From a mathematics education researcher:
That said, I have been up-front here on HN in suggesting ways that Khan Academy can improve, for example by building more online practice that is truly problems rather than exercises (379 days ago),
“Just for friendly advice to the Khan Academy exercise developers, I’ll repost my FAQ about the distinction between “exercises” and “problems” in mathematics education. It would be great to see more problems on the Khan Academy site.”
and the Khan Academy developers have been listening, and I have had interesting off-forum email interaction with them as they attempt to improve the instructional model at Khan Academy.
And here is the most important comment of all:
In general, I think mathematics is much too important a subject to be single-sourced from any source.
I’d add to that by saying that learning difficult things is really difficult. The best way of learning something is to learn it more than once and in more than one way. Khan is a free alternative way for people to learn math (or almost anything). This is incredibly valuable.
No teacher is going to be perfect but I’m sure that Khan is displaying above-average teaching competence in most of the subjects he chooses to teach. Khan will never be an outstanding teacher for his millions of students because there is something important in in-person instruction than cannot be replicated over video.
But very few students will have the opportunity to learn from more than a handful of outstanding teachers in their lives. For the majority of their experiences, Khan, and other instructors like him, will prove to be an immense help.
How many teachers are willing to expose their style for all to see and critique? Few, but those that do (look at this this article that suggets that teaching, like everything else humans do, is a skill) will become better at it. Good for us all.