Kathleen of the Otter Group has posted a weblog entry about an article written for the Univ. of Maryland's student newspaper called "Campus weblog use could explode"
A quote from the original article, focusing on Matthew Kirschenbaum, English professor:
"Three weeks into the semester, there are 125 student comments on my class blog," he said. "There's much less discussion on a course e-mail list than on a blog."
Kathleen also added an excerpt from an email between she and professor Kirschenbaum about the blog-based discussions vs. email lists:
Couple of reasons I think: one, like all the rest of us, my students now get a lot more email than they used to. Course-related mail gets mixed in with the usual jumble of spam and whatever else. All too easy just to hit the delete key. Two, the blog allows them to see their ideas instantly published on the Web. Email is a closed world, a self-contained loop between the instructor and the other students. With the blog, the fourth wall is always open.