Bond Graphs and ENPORT in Elementary Physics Instruction

This paper describes a problem-oriented programming system in which students can construct models of physical systems. The "bond-graph" notation is used for representing physical and engineering components and their interconnections, whether as a general and descriptive model or a specific and quantitative one. Using a simple linear notation the student enters the model into the computer via a standard keyboard and observes the behavior simulated by the ENPORT program. The results are given in function values and simple curves that reveal certain well known but instructional aspects of physics. A description is given of an instructional monitor that is capable of evaluating the student's model by comparing it to a "reference" model constructed by a teacher. The problem of interpreting differences between bond graphs in a way that aids student learning was not solved, but the student is given full access to ENPORT to bypass the problems of effective monitoring.