6. Managing Hybrid Model Composition Complexity: Human–Environment Simulation Models

Multimodeling approaches are increasingly required for simulating multifaceted systems across many scientific disciplines. Such approaches represent the system as a set of subsystem models, each with its own structure and behavior. Some multimodeling approaches use modeling methods to define how the subsystem structures and behaviors interact. However, modeling a system this way brings about subsystem and composition complexity that must be managed. The complexities of hybrid models resulting from the interactions of the composed models can be reduced using interaction models. Independently developing and utilizing such interaction models provides additional flexibility in system model design, modification, and execution for both the subsystem models and the resultant hybrid system model. This chapter discusses the use of the polyformalism model composition approach for researching human–environment dynamics with direct support for managing the complexity, which results from subsystem model interactions within this domain.