The virtual classroom under consideration supports students submitting exercise answers online and comments on exercise answers that include numerical scores. Automated quality control procedures track the student scores. The patterns of scores vary as a function of the pragmatic import of these student scores. Clear consequences of commenting must be enforced in the classroom before students will engage in fruitful commenting. The managerial problems that arise in courses that rely on extensive student-student commenting can be partially solved with automated tools that guide students to comment in fair and flexible ways.