[exch]

It's not portrayed in that way, no. Khan Academy seeks dedicated movie makers.

Letting the teacher do it instead can have its benefits. Certainly when it comes to teaching a customized or niche curriculum that simply isn't available on a place like khanacademy.org.

However, I do think that having videos recorded by people who excel at that kind of stuff (like Salman himself) also makes a lot of sense. A good voice and a clear way of explaining potentially difficult subjects can not easily be done by everyone.

One would say that a teacher should be able to do it, but talking to a computer screen is a lot different than talking to a classroom. And from my own experiences I know for a fact that not nearly all of them have the charm and capacity to convey a subject in an understandable and inspiring manner.