Styles, I. (2006, September 16). Linking Psychometric and Cognitive-Developmental Frameworks for Thinking About Intellectual Functioning. WebPsychEmpiricist. Retrieved September 16, 206, from http://wpe.info/papers_table.html
Two major approaches to understanding intellectual functioning - the psychometric and the cognitive-developmental approaches epitomised by the seminal work of Binet and Piaget, respectively - are here considered complementary rather than incommensurable and, in particular, as essentially manifestations of the same underlying construct but at different levels of scale. From this perspective, and by exploiting Item Response Theory, performances of persons on Ravens Progressive Matrices (exemplifying the psychometric approach) and performances on three Piagetian tasks (the Balance, Chemical Combinations, and Correlations tasks) are mapped onto a single continuum of intellectual development. The implication is that qualitative and quantitative conceptions of intellectual development are closely interlinked: within each cognitive-developmental stage, a series of small, incremental, quantitative changes occur and evolve into a major qualitative change in cognitive functioning. In order to clarify the nature of the transformations in thinking that occur at the transition points between one Piagetian stage and another a new taxonomy is developed to classify RPM items. Knowledge of the RPM items which are operational at each Piagetian transition indicates the transformations in thinking that are required.