ABSTRACT
A model, in the broad sense, is a representation of something, be it a physical or cerebral representation. In the sciences, models often begin as conceptual interpretations of experimental observations (Figure 8.1). Experimental observations (stage 1) lead to a qualitative concept (stage 2) and additional questions, which then require additional experiments (stage 3). At some point, sufficient knowledge is gained that quantitative representations, or models, arise (stage 4). Such models may take the form of physical models, for example, where a network of elastic tubes represent the arterial circulation. Commonly in medicine, the term model refers to an animal model, with the assumption that a particular animal’s physiology is similar to that of a human.
