Presenting systems concepts in Physiology and Pharmacology with simulation applets in Java

Java simulation applets solving equations for system models have been constructed for teaching system behavior in Pharmacology and Physiology. The applets are intended to be included in Web pages with text and other illustrations for use in the classroom or in self-study lessons. Students can experiment with the system by changing selected model parameters with sliders, immediately observing the resulting changes in system behavior. Several applet presentations are constructed for a model, each presentation designed for a different learning objective by displaying a subset of output variables and making a subset of parameters available for adjustment. Presentations may include control buttons, a graph for output display, sliders to adjust parameters, a legend table comparing parameter settings for multiple experiments, and an animation of the model linked to the calculations. The applet design is highly modular to facilitate replication with different models. Two architectures were tested and compared: 1) a single applet containing all the functions listed above embedded as a single unit in the Web page and 2) a cluster of individual applets of different functional types (control buttons, graph, sliders, etc.) distributed over the Web page and linked by a control object having no visible interface.