Nonstandard conditionally specified models for nonignorable missing data

In this paper I discuss some of the purposes and functions of building models, particularly agent-based models, and present a comprehensive list of these purposes and functions. Careful thought and attention is needed when modeling domains containing intelligent entities, which is usually the case for agent modeling. Reflection on the challenges involved in such domains leads me to propose the construction of meta-models, which are models of the relationship between an intended model of the domain and the entities in the domain, when the entities may have access to the intended model or its outputs. Agent-based computing approaches provide disciplined means of specifying, designing, developing and evaluating such meta-models.