But just "putting the video out there and seeing how people react to it" isn't "scientific research." Science involves testable hypotheses and controlled experiments. Just throwing things against the wall and seeing which ones stick is something different.
"Putting the video out there" is an experiment. It's not rigorously controlled, but it's about as controlled as a website is likely to get. So they put something out there, see how well it works, and maybe tweak it.
That's the very essence of scientific experiments. You don't always need a "hypothesis" to do science. (Or, if you like, the hypothesis is "This video will teach students to do X.")
Khan has a fairly extensive testing/data analysis system. He puts the material out there, measures whether students correctly answer the problems, and iterates from there.
While it's not controlled experiments, it's about as close as you can get in education.
