摘要:Background and Objectives: The use of online learning with virtual cases has become commonplace in medical education. A series of fmCASES has been developed to assist with learning for clerkship students in family medicine. It has not been shown whether this series of cases improves student learning during their clerkship compared to traditional learning modalities. Methods: We designed an intervention study to replace the traditional family medicine clerkship textbook with the fmCASES curriculum at one medical school. We then compared two consecutive cohorts of family medicine clerkship students by examining their performance on overall and small groups of exam questions at the end of the clerkship. Results: Data were obtained for 95% of students across the 2-year study. Overall performance on the end of clerkship exam was unchanged with the transition to fmCASES. Student performance was variable based on subject area and source of examination question. Conclusions: Using a set of online cases to replace a traditional textbook did not change overall performance on the end-of-clerkship assessment. However, our findings suggest that students demonstrated proficiency in answering questions that came from the sources they studied from. This finding should be considered when curricula transition to greater use of online learning resources.