It can be difficult to grade content in a self reflection assignment.  The content is personal and is based on the students perceptions.  There usually is no right or wrong. Students either do the assignment or minimum number of postings or they do not.  Assigning points for the completion of a the self reflection encourages students to participate but the total number of points should be nominal, i.e. 5% of your grade if you complete the assignment.

There are many ways to use self reflection assignments in a course.  In a clinical specialty like nursing the clinical reflection journal offers the student a way to express their feelings and anxiety about their role.  Reading other peoples journals helps students realize that this is a difficult process for everyone.