Stella: growing upward, downward, and outward [software review]

The author reviews Stella\´s modeling capabilities for both research and instruction. He describes the basic modeling tools using his student\´s quest as a simple, illustrative case study, exploring how these tools contribute to speed and efficiency in creating models for concept testing. He also examines some of Stella\´s broader research capabilities in the context of how they support and connect with more specific and scalable modeling systems implemented in high-end systems. Finally, he comments on Stella\´s range of educational applications. Stella (www.hps-inc.com) is a modeling application that can serve such needs, although it makes a relatively expensive scratch pad. Fortunately, it also provides other capabilities that add to its value as a productivity tool, just as a spreadsheet application lets you both build certain kinds of models and formulate a budget. Stella has several component toolsets, and its user interface is organized in layers. As such, the test of the application\´s total value is not just in its range of functionality but also in how well its toolsets and layers are integrated. The premise underlying Stella\´s design is that "systems thinking" is important for solving a wide class of problems and that there is a need for tools that support and cultivate this methodology.