I’m planning on introducing blogs to my freshman composition courses this fall. I’ve done discussion groups using Web Crossing, and I found that the best way to require students to communicate with each other was to require it. I often used the vague carrot (“responding to other students will be rewarded”), and quite often it worked well enough. I think it did help that studnets at Georgia Tech are usually adept at computers and often have a collective/collaborative spirit based on the difficulty and heavy work load of most of their courses.
I’m still thinking about how to incorporate the blog into a composition course. I think I want to leave evaluation somewhat open to allow students alternative ways of constructing their online identities via blogging.
I know that Jill Walker (on/in my blogroll) has had some success with using blogs in her classes, so that’s another useful source.