Why live streaming improves the grades of those who are doing well and lowers the grades of those who are struggling? We imagine it relates to the fact that when live streaming isn’t available, struggling students will make the effort to come to class even when the cost is high, while the best students will be tempted to skip class and learn on their own. When live streaming is available, however, struggling students will watch the lecture online instead of going to class, which hurts their grades, but the best students will watch the lecture instead of learning on their own, and this lifts their grades.

Quelle: Are online teaching materials emptying out university classrooms? – EPFL