When I was in college there were study groups. I did not belong to a study group, so I do not know a great deal about them. What I do know is that at least some of the groups would meet at the library once a day, to share notes, to share information, or whatever else they needed to share or discuss.
I am not sure how a forum would be a better way for a study group to meet than a "face to face" meeting would be, but I guess whatever works is the way to go. I know a forum works well for people who are not in the same place, but if you are part of a college study group I would think the members would be in fairly close proximity and meeting "face to face" would be fairly easy. But if you prefer to have a forum, that is perfectly fine, I am not trying to start an argument with you. I am just saying to my mind it makes more sense for a study group to meet in person rather than trying to get together on a forum and having to type everything rather than just talking.