Stephen Downes has written an interesting Educational Blogging article in the Educase Review, "looking at the nature and history of blogging, educational applications, tools and technologies, trends, and early experiences in educational blogging."
The example given at the beginning of the article reflects on an example weblog community with three different types of blogs being used by the students and teachers:
"This virtual space is composed of three sets of weblogs, or blogs: a classroom Web space, where announcements are displayed and work of common interested is posted; a public, personal communication zone, where students post the results of their work or reflection; and a private personal space, reserved for students’ thoughts and teacher guidance." and the point of this is "to promote reflective analysis and the emergence of a learning community that goes beyond the school walls."
There is a more detailed description of the workings of this at the Institut St Joseph site, and the public 'tutor' weblog site and the 'class and student' weblog site can also be examined.
One thing I find is interesting about this project, which looks highly organised and professional, is the avoidance of using the term 'blog' or 'weblog'. They use the term 'cyberportfolio' instead, which does not need explanation. In the past, I have had problems communicating to students the concept of the 'weblog', and some students ended up thinking it was a kind of 'forum', but this was not a good idea, especially a forum is an impersonal space that people contribute to sporadically and infrequently, and the idea behind a weblog is that the contributions should be regular and personal.
The article also discusses many aspects of educational blogging, including the idea of using a weblog to assign homework. This is frowned upon. It is also noted that "many writers have noted, writing a weblog appears in the first instance to be a form of publishing, but as time goes by, blogging resembles more and more a conversation."