A Docking Study of SimVision and ORGAHEAD

Following the efforts of Axtell, Axelrod, Epstein, and Cohen (1996) to “dock” the Sugarscape model and the Axelrod Culture Model (ACM), the current paper reports the results of a current drive to dock the SimVision and the ORGAHEAD models. Docking is a term coined by Axtell et al. to describe the process by which two models are made to give equivalent results. Establishing equivalence gives the models’ designers confidence to say that their model can reproduce the other model’s results. This gives both models a greater sense of validity. The process of docking, regardless of equivalence outcome, is perhaps the most fruitful part of the endeavor. The docking process lays bare the similarities and differences between the two models, making it easier for others to see how the models relate. Future modelers will have gained insight into the effects of various computational features. In addition, by uncovering the operational and representation differences we can understand the extent to which each affects model outcomes. In this sense, the docking process serves as a sensitivity analysis of model features on model outcomes. While striking differences exist between SimVision and ORGAHEAD, both models can support the same types organizational forms, have a concept of a task, and model individual actors with access to certain resources or skills to solve tasks. How these are represented in the two models differ greatly, but that is part of the reason why attempting to dock these two models can be so valuable. To lay the foundation for the paper, a brief description of the two models is given first, followed by a description of the data used to dock. Measurements by which the two models will be compared are explained and finally, the results and observations from the docking process are presented.