I think that one of the most interesting side-effects of blogging, is when your students begin to blog. Generally, when people begin any form of on-line journaling, they feel a little bit more free to express themselves. Sometimes these student-bloggers are anonymous, which brings even more freedom to speak one's mind. Their thoughts and feelings begin to pour out on a computer screen and sent off into the world. And many times things that never would have been shared vocally, are being shared.
When these blogs are not anonymous, but the writers are still very free with their thoughts, this can lead to trouble. There are many that just spout off too much, then people are hurt and/or offended by what has been written.
Sometimes students will do new postings and read each others blogs on a daily basis. When this happens, it almost becomes a little community. This kind of student blogging is the most interesting. When students begin sharing their real feelings on different topics, such as school policies, or theological questions, you really begin to know who these students are.
As a teacher, this kind of information is invaluable. Especially as a teacher that likes to take "rabbit trails" knowing what is interesting to the students helps to have well-placed diversions.
Next year I am teaching a class called Self-Confrontation. I am already pretty excited about this class. I am mentioning it right now because I am thinking about requiring a journal for the class. And because of the ease of the current blogging environment, I am strongly considering having them do an online journal. It would have to be separate from their current blogs, if they have any, and it would be a spiritual/devotional journal. Nothing too personal, but informative. A what are you learning journal.
Last year I helped the English teacher, at the school where I was teaching, set her students up with blogs. She would then post a topic occasionally and then check to see if her students had posted about that topic. It worked really well, or so I thought, but it also made the journaling a little bit more interesting to them.
I think that sometimes it is good to try to incorporate their current interests into the curriculum in any way that is possible. Unfortunately, it might be a little bit more difficult to have a math blog...