Testability and meaning of mathematical models in social sciences

Abstract The terms “model,” “theory,” and “law” are being used with a variety of meanings in practice as well as in theory. Depending on the definition of the contents of these terms they have to satisfy different requirements. The author focuses his attention on mathematical models and their use in Operations Research and Management Science. After pointing out the difference between “theories,” “laws,” and “models,” criteria for the quality of models are defined and problems of model building discussed. It is considered particularly important that factual models—as opposed to formal models—are designed in such a way that they are testable. A factual model which is not testable can neither be confirmed nor falsified and can therefore never claim to be factually true. Problems and ways of building and testing models in the social sciences are then illustrated by considering approaches to model human decision making in fuzzy environments.