In a forum, a rating is really a grade. When you enable ratings, you are really allowing the teacher to give each forum posting a grade. In the following screenshot, you can see the first posting in the forum, which was made by the teacher. After this, you can see the reply left by Student1. The student's reply was rated by the teacher:

By default, only teachers, non-editing teachers, and course managers can rate forum postings. If you want students to be able to rate postings in a forum, you must enable this for the forum. You do this on the Permissions page. Before leaving the Settings page, save your work.

To enable students to rate forum postings, perform the following steps:

1. Select Forum.
2. Then, select Settings | Forum administration | Permissions.
3. From Advanced role override, select Student.
4. A page listing the student's permissions for this activity is displayed. Scroll down to the section labeled Activity: Forum and locate the permission for Rate posts.
5. Select the Allow radio button.
6. Click on the Save changes button.