Flexible modelling with VSEit, the versatile simulation environment for the Internet

Social science research calls for the explorative modelling of complex problem domains. A modelling tool that aims at supporting this kind of effort has to strike the balance between offering sufficient flexibility for free exploration on the one hand and effective measures to relieve the modeler from the more cumbersome parts of programming on the other. The Java-based VSEit framework, presented in this paper, embodies a pragmatic approach to strike that middle ground. One key element of the VSEit architecture is the supplementation of the usual object-oriented class concept with the capability for specifying types of model entities and structures at a high semantic level.