This workshop is supported by NSF and is for invited participants only who are working with sets of Diagnostic Question Clusters (DQCs) designed to improve the reasoning and learning of students in general biology courses. The DQCs were developed by education researchers at Michigan State University who analyzed students' responses to questions about core biological concepts and ideas; problematic patterns in students' thinking were used to develop systematic approaches to biology content. Faculty participants who have been using the DQCs and active teaching to reform introductory ecology and biology courses will continue to work together in this session.