Describing Human Decisions in Agent-Based Social-Ecological Models - ODD+D an Extension of the ODD Protocol

Multiple agent-based models (ABM) on social-ecological systems exist in parallel investigating similar research questions. However, the choice of a particular human decision model is often not sufficiently empirically or theoretically substantiated in the model documentation. Furthermore, model comparison is difficult because model descriptions are often incomplete, intransparent and difficult to understand. Therefore we expand and refine the ‘ODD’ (Overview, Design Concepts, and Details) protocol to establish a standard to describe ABMs which includes human decision making (ODD+D). Since the original ODD is mainly from an ecological perspective, some adaptations are necessary for the social-ecological context. We extended and rearranged the design concepts and related guiding questions to differentiate and describe decision making, adaptation and learning of the agents in a comprehensive and clearly structured way. Furthermore, ODD+D encompasses a section on ‘Theoretical and empirical background’ to encourage that model design and model assumptions are related more closely to theory. The application of ODD+D is illustrated with a description of a social-ecological ABM on water use. We believe that our expansions help to make the ODD protocol a most suitable protocol to describe social-ecological ABMs and may support the review process of related manuscripts. The ODD+D protocol does not only improve the quality of model descriptions but also improves our understanding of models and is an important necessary step forward developing theory respectively frameworks for social-ecological ABMs.