The sequence of development as hypothesized by Piaget has been confirmed for various groups of children by cross-sectional and longitudinal studies. Such consistency has increased interest in constructing scales based on Piaget's theory according to psychometric principles. Three major problems are discussed which present definite obstacles in the…

The purpose of this study was to design a prototype written test of cognitive development based on the model of Piaget. Although the results were not consistent with Piaget's theory, test development was only partially successful. Specifically, validation of the scales was excellent or poor depending on the perspective. Analysis of the item…

Theory and research regarding four levels of concept attainment and three uses of concepts as specified by the model of conceptual learning and development (CLD) are described. Subtests, utilizing three-dimensional stimuli, were developed to assess each level of attainment and each use of the concept equilateral triangle. The tests were…