Mental models are one way that humans represent knowledge (Markman, 1999). Instructional design (ID) is a conceptual model for developing instruction and typically includes analysis, design, development, implementation, and evaluation (i.e., ADDIE model). ID, however, has been viewed differently by practicing teachers and instructional designers (Kennedy, 1994). In a graduate ID course students constructed their own ID models. This study analyzed student models for (a) what ADDIE components were included (by teacher, nonteacher), and (b) model structural characteristics (by teacher, nonteacher). Participants included 178 students in 12 deliveries of a master's level ID course (115 teachers, 63 nonteachers). Our conceptual ID model is presented, and the ID model task is described. Students most frequently represented design, followed by program evaluation, needs assessment, development, and implementation. In terms of structural characteristics, 76 models were characterized as metaphoric, 61 dynamic, and 35 sequential. Three interrelated conclusions and implications for ID learning are offered. (Contains 4 figures and 4 tables.)