Concept map (CM) is introduced as a useful tool for studying students' system thinking (ST). However, it is more known to represent students' knowledge of system components and organization and less recognized as a tool to examine and enhance students' understanding about the underlying causal mechanisms in complex systems. In this study, through…

This study follows two groups of students (67 in all) through the 3 years of their high school biology education and examines the development of their systems thinking--specifically their models of the human body as a system. Both groups were composed of biology majors, but the students in one group also participated in a PBLbased extension…