Over the past eight years we have undertaken iterative cycles of course reform in two introductory biology courses: Biology 111 and Biology 211. Our revisions of these formerly "traditional" lecture courses have included in-class case studies with and without peer facilitators and peer-facilitated small-group workshops. Based on analyses of overall pass rates, as well as pass rates by gender and by underrepresented minority (URM) status, we have found that there are differences in the effectiveness of alternative course models in the two courses. In Biol 111, required peer-facilitated workshops improved overall student performance, especially for URM and female students (Preszler, 2009). Here we report that similar workshops were not as successful in Biol 211, but that in-class case studies facilitated by peer instructors have improved student performance and reduced the performance gap. Clearly, what is the "best practice" for one course is not the best practice for the other.