VisiGarp: Graphical Representation of Qualitative Simulation Models


Anders Bouwer and Bert Bredeweg

Social Science Informatics, Department of Psychology, University of Amsterdam, Roetersstraat 15, 1018 WB, Amsterdam, The Netherlands Tel: +31-20-5256784 Fax: +31-20-5256896 E-mail: {anders, bert}


Keywords: Knowledge visualization, diagrammatic representations, simulation-based learning environments, qualitative reasoning

Abstract: Qualitative simulation models can play a useful role in computer-based learning environments, since they explicitly represent the domain knowledge required for causal reasoning about system structure and behaviour. However, the amount of information involved in a simulation is often large, which makes it difficult to transform the computer's reasoning trace to effective explanations. Research on natural language explanation generation has made a lot of progress in the last two decades, but in addition to text, graphical representations also play an important role in the communication of knowledge. For example, state-transition diagrams, causal networks, structural hierarchies, tables and graphs all use different visual primitives to create a context for communication, and to denote relationships between the different kinds of entities. The structural information encoded in these graphical representations is hard to communicate using only text. Although several kinds of automatic visualization already exist, many of these are tailored to specific domains, or types of data, e.g., numerical data. Our goal is to develop generic mechanisms for automatic visualization of qualitative simulation models, and to integrate these mechanisms into a framework for generating multimedia (text and graphics) explanations. Currently, we have developed an interactive model inspection tool,VisiGarp, which automatically generates several kinds of diagrams from a qualitative simulation model; a mouse and menu interface allows flexible switching between these different views on the model, providing both overview and detail. Further work includes layout optimization, aggregation and abstraction mechanisms, and integration of graphics and text generation.


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