When multiple forum posts are rated for the same student, moodle only averages the scores. It would be better if it allowed for more options such as only taking the highest or dropping the lowest rating for each student within a forum. Currently the gradebook can drop the lowest score in a category, but this does not apply to forum posts by the same student within the same forum. This is because each forum is a separate assignment in the gradebook regardless of how many times a student posts to a particular forum. I propose these advanced rating options:
Average ratings from multiple posts from the same student.
Take highest rating from multiple posts from the same student.
Drop the lowest rating from multiple posts from the same student and average the rest.