My friend Matthew is thinking about producing some instruction math videos online and had some great thoughts about the videos on Kahn Academy:
I watched the first part of his 8-minute Basic Trigonometry lecture, and the first 30 seconds are devoid of any content. I bet he lost half his potential viewers in the first 30 seconds. When I make my videos, the point will be immediately obvious in the first 5 to 10 seconds, and I think I’d want to keep the length to two or three minutes.
Matthew: It would be interesting to analyze more of the popular educational videos on the web and break them down. Learning isn’t knew, teaching methods have been around for a while.. so who is doing it best? I remember when MIT starting providing their (entire?) academic library available on their website for almost free- and people around the world were using that as their main learning source, while other kids (a high schooler who was an overachiever with an unimaginative High School Math instructor) were using the curriculum in addition to their normal school, IE: “I like watching the [MIT Math Professor]. He’s passionate and makes it interesting.”
On making the point obvious in the first 8 seconds: Wired did an article SciFi network producing their own low-budget movies several years ago. Their production team laid down several goals- one of which was “You have to see the monster in the first 5 minutes!” I love it. They knew we don’t wait in suspense the entire movie, catching dark shadowy glimpses of the monster. We want to see it! That is one reason we are watching.
Same thing for your math students. Get to the point. Good call!