I came across this excellent video from Daphne Koller which goes into detail about how about how the Coursera system works for Massive Open Online Courses. What is fascinating to me is how they are taking advantage of the online nature of the medium. What I mean is that even though you are one of a 100,000 students, you can progress at your own pace with embedded assessments. As I have mentioned, I believe any solutions for online education must work on a global scale. This one does. (see Higher Education For The World)
This is well worth 20 min of your time.