ABSTRACT
A model may be defined as a computational or physical construct that has some functional equivalence to a real system. Hypothetical essential properties of the real original system are represented, while the potentially confounding irrelevancies are ignored (1). Models may be useful in the understanding of relationships between cause and effect in a complex physiological or pathological process. Their great strength is a flexibility that is not possible with an intact system. Their great weakness is that they are critically dependent on the assumptions made in their construction. The critical importance of these two considerations must always be kept in clear perspective when attempting to construct a model of a biologic process (2). The general principles and philosophical premises of modeling in biomedical research have been reviewed in detail (2).
