On the Cohort Membership screen, a user can hover over the entries in the "projects" column to view a title attribute containing a list of the projects for each cohort member. This is useful. However, there is no indication of this feature in the UI, so the user will only discover it by accident. The text in the "projects" column looks the same as the text in the "username" or "valid" columns, even though those values don't have associated tooltips.
Suggestion: Instead, use an actual tooltip icon next to each value under "projects" that has multiple values.