Khan Academy & the Effectiveness of Science Videos

It is a common view that 'if only someone could break this down and explain it clearly enough, more students would understand.' Khan Academy is a great example of this approach with its clear, concise videos on science. However it is debatable whether they really work. Research has shown that these types of videos may be positively received by students. They feel like they are learning and become more confident in their answers, but tests reveal they haven't learned anything.