In this professional development series for science teachers, unscripted visits to real classrooms capture inquiry-based science instruction as it unfolds. Each program begins with the teacher explaining his or her goals for teaching a particular science concept, then follows several days of class work-complete with the normal changes of plan and interruptions-as students observe, analyze, develop theories, and reach conclusions. The teacher then gives a candid review of the class response and of his or her own lesson.