This presentation will examine how the conceptual representation from structure-behavior-function theory can be used as a tool for thinking about complex biological systems A study of expertise demonstrates that experts consider two complex systems in terms of structures, behaviors, and functions whereas novices represent these systems largely in terms of structures. Based on these findings, an experiment was conducted to test these ideas in the use of hypermedia before developing a larger unit of classroom instruction that focused on function. This presentation will discuss the tools that were developed to help make behavior and function visible, how they were enacted in different classrooms, and what students learned.