ABSTRACT
Influential critiques (e.g. Brown and Desforges, 1977; Lawson et al., 1978; Case, 1991) have discounted the validity of Piaget’s theory of intellectual development specifically on the grounds of the poor psychometric evidence that existed for the relationships amongst tests of concrete and of formal operational thinking. It would be straightforward to demonstrate that such claims are, at most, marginal to Piaget’s epistemology, given the gulf between the explicit philosophical foundations of Piaget’s theory in rationalism and structuralism and the implicit empiricist orientation of the criticisms. However, given that Piaget’s theory has been popularised as one informing educational (and psychological) assessment and intervention, it would be avoiding the issues to argue that the theory should be evaluated strictly on its own philosophical terms (see Bond and Jackson, 1991; Smith, 1993). But it does not seem unreasonable to require of any psychometric evaluation of Piagetian theory that, at least, the psychological or educational tests being used must interpret Piaget’s theory in its own terms, and the statistical analyses must be sensitive to the expressly developmental nature of Piaget’s explanatory account.
