The Relation between Idealisation and Approximation in Scientific Model Construction

Abstract

The notions of ‘idealisation’ and ‘approximation’ are strongly linked to the question of ‘how our theories represent the phenomena in their scope’. Although there is no consensus amongst Philosophers on the nature of the process of idealisation and how it affects theoretical representation, at the level of science education much can be gained from the insights of existing philosophical analyses. Traditionally, teaching methodologies treat the observed divergence between theoretical predictions and experimental data by appealing to the more common-sensical notion of ‘approximation’. The use of the latter notion, however, to explicate discrepancies between theory and experiment obscures the theory/experiment relation. It does so, I argue, because from the viewpoint of scientific modelling ‘approximation’ either depends upon or piggybacks on ‘idealisation’.