Forum ratings can be customized with a specific aggregation method and custom scale (see this article for instructions - Grading Forums, Glossaries and Databases Using Ratings).
By default, instructors and TAs with gradebook privileges will be able to rate, edit, and view the aggregated forum totals for each post.

It is possible to give students additional privileges to rate forum posts as a collaborative activity with control over whether or not they can see each posts total aggregated score and/or who has provided what ratings - Allowing Students to Rate Forum Posts (Peer review).
So while whole forum grading is best for instructors who want to look at a course participant's posts and give it a direct grade, or to mark using grading methods like marking guides or rubrics, forum ratings are best for if you want to mark it based on a certain aggregation method, such as the average of all ratings of a student's posts in a forum over the course duration, or if you want to students to rate each other's posts.

Rating Forum Posts

1. After setting up the Forum Ratings, at the bottom of each post (and reply) in a forum, instructors and TAs will see a Rate dropdown menu with their chosen aggregation method and scale. Select the desired value from the dropdown to rate the forum post.
   
   
   
   
2. Once you specify a rating, the page should refresh to reflect the addition of your rating to the aggregation. This will be visible immediately to the left of the rating dropdown in the form of 2 numbers: the first number displays the aggregated rating and the second number enclosed in the brackets indicates how many people have rated the post (ie. the number of ratings used in the aggregation). For example, 3(1) means that the forum post scored a 3 based on one rating. Note that students do not see the aggregated score or count for ratings.
   
   
   
   
3. Once a forum has been rated, clicking the two numbers will show the instructor a summary of which other instructors or TAs have provided ratings and their score. This summary view can be useful in collaborative situations when students have been given rating capabilities.
   
   

Navigating within forums to facilitate grading in forums:

1. If you ever need to return quickly to the main forum page listing all topics, click Forum.
2. You can navigate to the previous or next post in a forum by clicking the topic title and arrows at the top and bottom of the current post and replies.