This document describes the Conceptual Learning and Development (CLD) model of concept formation. According to the CLD analysis, a single concept is learned in the following successive levels of attainment: concrete, identity, classification, and formal. The four levels are considered applicable to concepts that are defined (or could be defined)…

The purpose of this study was to empirically test a set of predictions implied by the Model of Conceptual Learning and Development using the concept of cutting tool. Four subtests were developed to assess a subject's ability to perform at each of four successive levels of concept attainment (concrete, identity, classificatory and formal). In…

For this study, the second in the cross sectional series, based on the Conceptual Learning and Development (CLD) model, assessment batteries were developed to determine each child's level of attainment and related use of the concepts "equilateral triangle,""cutting tool,""noun," and "tree." Batteries were…

For this study, the second in the cross sectional series, based on the Conceptual Learning and Development (CLD) model, assessment batteries were developed to determine each child's level of concept attainment and also the related use of the concepts "equilateral triangle,""cutting tool,""noun," and "tree."…