Pins are "public" (i.e., viewable by everyone in class) and are typically coupled with the poster’s real name. And learners know that posts are viewable by the board owner, even when they post anonymously. It would be fairly unusual for a learner to stand up in a classroom and start yelling at another learner in front of the instructor and the rest of the class. Similar social pressures dictate acceptable behavior within a Yellowdig community and instructors can easily set the expectations of the community and re-iterate them as necessary on the rare occasions where a problem would arise.
Aside from the social situation and instructor guidance, as long as instructors award points for the actions, learners know they can receive more course points when their peers Upvote their discussion. Or that other learners can mark their content as “Not relevant,” which can lead to instructors deciding to revoke points for poor content.
Finally, instructors considering the platform often voice concerns about post quality or learners getting points for leaving short, thoughtless commentary. By default, Pins and Comments have a required word count. Our data shows that requiring more words actually encourages generation of complete sentences and posts with a higher average reading level. With Upvotes and the social expectations, we find that most instructors that are new users of our platform are pleasantly surprised by the quality of Pins and Comments. All of these design features incentivize and guide learners towards creating high-quality, thoughtful, and well-articulated posts while also dissuading anti-social behavior (e.g., “trolling”).
Why? You shouldn’t expect the negative because it rarely happens. To put it bluntly, there are real social and academic consequences for acting like a jerk within a learning community when points and grade passback are enabled. Yellowdig boards very rarely require policing.