Students often bring considerable prior information about the Holocaust to their study of the event, with much of that knowledge being inaccurate or incomplete. In addition, the Shoah's complexity necessitates that teachers establish a well-defined framework as they introduce the topic to their students. This article outlines an opening lesson for a Holocaust unit in which students develop a definition of the event by completing a multistep process that deconstructs the United States Holocaust Memorial Museum's definition of the Shoah. Through this process, teachers gain valuable information about students' prior knowledge while establishing a structured approach to the teaching of the event. In addition, students' content knowledge of the Shoah is expanded as critical topics about the event are introduced at the start of their study of the topic. (Contains 4 notes.)