Despite being relatively early and ad hoc, Khan academy got it mostly right: don't just tape someone giving a lecture; give a close up of the instructor writing out the logical profession of ideas. In a classroom, it's too hard to do it fast enough; they either have to write very little, or use static slides. Khan wisely used the virtual whiteboard, in effect, to accelerate the writing speed while having infinite space and instant jump-around.
I still prefer the mostly-webpages approach, but Khan definitely did a lot more to make use of the format than "dump a camcorder in a lecture hall".
Exactly. I used KA to review some differential calculus and was surprised to see how effective the basic chalk-to-the-blackboard (digital pen, in this case) approach still was.
It is also the reason why I prefer MIT's OCW video lectures over their edX ones. I like how most of the lecturers often take the time to write down the terms and ideas on the blackboard in the old-school way.
I find learning that way helps drive home the concept in a more concrete way than flipping slides with voice-over. I believe this is especially important in case of subjects like math where 'doing' is perhaps the only effective way I am aware of learning the material.
I still prefer the mostly-webpages approach, but Khan definitely did a lot more to make use of the format than "dump a camcorder in a lecture hall".