Thanks to Peter Rowlett for providing me with the following interesting link:
College 2.0: More Professors Could Share Lectures Online. But Should They?
This is an interesting discussion!
Of course, I have been putting podcasts/screencasts/videos of my classes online. This is very popular with my students. However, it does not appear to lead to significantly better overall student performances. I think that some students actually do worse than if the videos had not been made available. This is because they can allow themselves to fall behind, “secure” in the knowledge that they can catch up whenever they want. Unfortunately, this tends not to work out very well!
The article above (and comments on it) do give suggestions for addressing this sort of problem (e.g. student attendance at classes), and I will try some of these ideas out.