Introductory science and math courses at four-year universities serve several purposes, one of which is to act as gatekeepers to STEM majors. It’s easy for students to get lost in rigorous materials and the lecture hall. Those who succeed may proceed onto upper division courses, while others should consider another major. However, several universities, including the University of Colorado, UC Davis and the University of North Carolina are rethinking the introductory science experience by focusing on how the classes are taught. Students, even in massive lecture halls, are breaking up into groups, working out problems during the lecture and are held accountable with rigorous questions on the spot. Instructors are quizzing students and using real-time results to assess how well students understand the material. According to the New York Times:
"The University of Colorado, a national leader in the overhaul of teaching science, tested thousands of students over several years, before and after they each took an introductory physics class, and reported in 2008 that students in transformed classes had improved their scores by about 50 percent more than those in traditional classes.
At the University of North Carolina, researchers reported recently that an overhaul of introductory biology classes had increased student performance over all and yielded a particularly beneficial effect for black students and those whose parents did not go to college."
http://www.nytimes.com/2014/12/27/us/college-science-classes-failure-rates-soar-go-back-to-drawing-board.html