In fact, controlled studies show that video lectures are rather ineffective.
I would assume that studies comparing a competent physics teacher to a video instructor would show the former being more effective.
However, there is a shortage of competent physics instructors. There is a (possibly bigger) shortage of competent maths teachers. I am speaking from my more extreme experience in South Africa, where most of the teachers are abysmal. Expensive video-based instruction helped me achieve a respectable mark in physics/chemistry, most of my peers lacked that privilege and did very poorly. Even at university, things like differential equations, linear algebra and calculus were not particularly well taught - most professors are not really good at teaching, and in my case, they were teaching in a second language (Afrikaans speakers teaching English speaking students). The Khan Academy would have helped me even at the undergraduate level.
I have posted to HN in a related thread about video instruction in South Africa [ http://news.ycombinator.com/item?id=2351100 ]. People have been doing it for years here. I would recommend a controlled study in South Africa using KA, or The Learning Channel videos by William Smith (NOT run in an elite private school, but at an average township school) before we write off video based instruction as "ineffective".
I would assume that studies comparing a competent physics teacher to a video instructor would show the former being more effective.
However, there is a shortage of competent physics instructors. There is a (possibly bigger) shortage of competent maths teachers. I am speaking from my more extreme experience in South Africa, where most of the teachers are abysmal. Expensive video-based instruction helped me achieve a respectable mark in physics/chemistry, most of my peers lacked that privilege and did very poorly. Even at university, things like differential equations, linear algebra and calculus were not particularly well taught - most professors are not really good at teaching, and in my case, they were teaching in a second language (Afrikaans speakers teaching English speaking students). The Khan Academy would have helped me even at the undergraduate level.
I have posted to HN in a related thread about video instruction in South Africa [ http://news.ycombinator.com/item?id=2351100 ]. People have been doing it for years here. I would recommend a controlled study in South Africa using KA, or The Learning Channel videos by William Smith (NOT run in an elite private school, but at an average township school) before we write off video based instruction as "ineffective".