This chapter provides a brief overview of the set of cases and provides four suggestions—temper the impulse to evaluate the teacher; focus on understanding the students’ thinking as inquiry; support interpretations with specific evidence from the case; and recognize but tolerate incompleteness and uncertainty—for facilitating discussions. One practical suggestion about the order in which to use the materials within a given chapter is also provided—watch the video before reading the teacher’s account. The following Chapters 4-8 are the case studies.