In this study, one section of a chemistry course was taught using traditional lecture methods and the other had students solve problems in groups. Both sections took the same exam and those that finished the class had similar grade distributions. However, 33.3% of the lecture students dropped the class, as opposed to only 17.3% of the cooperative-learning students. The cooperative-learning students asked the instructor more questions in class and in office hours.
Abstract with link to full text (pdf)
