Why not go right for the throat?
How about I just round up all of the instructors who teach courses with group assignments, and ask them why code review tools aren’t provided or encouraged. Or maybe they’ve tried, but they ran into a stumbling block. Or perhaps the whole idea of using code review tools flies in the face of some important teaching method.
I won’t know until I ask. So why not just ask?
It might not be a quick, sharp, clever scientific study, but it sure might generate some interesting material for examination.