Interestingly, is has been proved that on average, studying in groups raises performance and grades enormously. Uri Treisman, spent a year at Berkeley trying to discover why some students who were exceptional in high school were failing out of freshman calculus in droves.
He filmed the study sessions of different groups and found that those who studied together had big advantages. They would correct each others mistakes and save great deals of time that way.
True, sometimes one mistake would mislead the whole group, but soon it was found and correectd by everyone.
It was also important to focus on studying the material in depth, i.e. working on hard problems, and spending sufficient time.
In particular, minority students from disadvantaged high schools who had developed the method of studying alone presumably to overcome the non academic culture of their surroundings were especially at risk in college, where the material was simply too hard and too voluminous to master alone.
Treisman devised a program that forced members to study together regularly and intensively, and focus on the hard problems in the course. His results are spectacular.
The students in his program, including large numbers of minorities, soon transformed themselves into the best students in calculus at Berkeley. He extended the program throughout the curriculum and he began single handedly producing most of the minority mathematics PhD's in the entire country.
He is extremely well known for this work, and continues it today, i believe in Texas.
I once read his entire published study, and we reproduced the program at Georgia for a while, but there was not sufficient student interest to make it permanent.
I.e. many students were not willing to devote extra time to a course just to do better in it, they wanted more credit hours for it as well. It also requires significant faculty commitment. But the method works.
