Principles of Model-Building

Abstract

For most people, discussion concerning a model provokes thoughts of some kind of physical representation of a real object—usually in miniature form. Such models will look like and often function in a similar (though often markedly simplified) way to the real object. Such physical models (classified as ‘iconic’ by Churchman, 1971) embrace children’s toys, tailor’s dummies and mock-ups of buildings and structures to be later constructed in real form. Representation of town planning developments or of the prospective layout of controls in a nuclear submarine are examples of useful iconic models and illustrate the point that models can be constructed of objects or situations not yet in existence in real form. It is not only miniature or life-size iconic models which prove useful; chemists, for example, find it expedient to construct greatly magnified physical representations of the structure of complex molecules. There is, however, an extremely useful class of model which bears little or no physical resemblance to the system it is intended to represent and it is this type of model which will be our major concern in this book. Churchman (1971) classifies such models as ‘symbolic’. Symbolic models are abstract in form and are perhaps more difficult to comprehend than iconic models. The abstraction of the model frees it from the limits of physical form, thus rendering this type of model considerable flexibility in both the mode of its construction and the manner of its use.