Metamorphic validation for agent based simulation models
Effective validation of complex simulation models is often very difficult, especially when data does not exist to perform result validation through comparison of outputs of a simulation run against the real world. This situation is similar to the problem faced during verification of computer programs for which there does not exist an "oracle" to test correctness of the output. Software Engineering researchers have developed an alternate technique known as metamorphic testing, that uses a set of related input output combinations called "pseudooracles." We propose a modified version of metamorphic testing that can be applied for simulation model validation, called metamorphic validation. Our new approach can be highly effective in building confidence toward establishing the validity of complex simulation models through the systematic process of discovery and application of metamorphic relations. We present the detailed process for applying this technique on agent based simulations. We then utilize a case study to show the successful application of metamorphic validation for validating a previously published multi scale agent based model of cancer.
SummerSim