Validation Without Data - Formalizing Stylized Facts Of Time Series

A stylized fact is a simplified presentation of an empirical finding. When modeling and simulating complex systems and real data are sparse, stylized facts have become a key instrument for building trust in a model as they represent important requirements regarding the model’s behavior. However, automatically validating stylized facts has remained limited as they are usually expressed in natural language. Therefore, we develop a formal language with a custom syntax and tailored predicates allowing modelers to unambiguously and succinctly describe important (temporal) characteristics of simulation traces or relationships between multiple traces via statistical tests. The proposed formal language is able to express numerous facts from the literature in different application domains, as well as to automatically check stylized facts. If stylized facts are defined at the beginning of a simulation study, formally expressing and checking them can streamline and guide the development of simulation models and their successive revisions.