When I was a professor (natural sciences) I decided to play around with different learning systems to see what worked best. I discovered the obvious that learning depth is negatively correlated with the student evaluation of their lecturer during the course and positively correlated a year later (students hate learning when they do it, but love the subject so much later that they choose your next course the following year because they learnt so much).

The more useful thing I discovered was getting the students to read the lecture notes before a lecture boosted the class average by 10% points. 10 minutes spent reading the lecture notes before the lecture and answering a few simple online multiple choice questions about the lecture was surprisingly effectively at improving learning. My assumption is it cut down on the novelty overload effect where the student’s brains shut down mid-lecture and so they were able to get more out of the lectures.