A blog is a publication mechanism, like a journal or bulletin. Blogs can promote open dialogue and encourage community building in which both the bloggers and commenters exchange opinions, ideas, and attitudes. Teachers can use a blog to publish instructional materials that the students can access to and where the students can make comments. Teachers can also let students set up their own blogs for a particular subject or for several subjects and then assign tasks to students. The tasks should be done using blogs (i.e., publishing articles and sharing them with other students). While the students develop their own blogs, teachers can observe and monitor the students' progress, and identify the learning needs that have not been considered (e.g., students may directly or indirectly express their doubts on blogs). As the information on students' blogs are growing, teachers need to classify, summarize and evaluate different students' blogs and then publish the teachers' opinions, directions, and feedback on their own blogs or on class blogs. By doing this, teachers are actually putting students to the right tracks, because if you just let students publish what ever they like, the use of blog could be out of control, and the relevance between the blog and the content being taught and learning will be reduced.