The Test of Logical Thinking (TOLT) is a written test of cognitive development constructed to be logically equivalent to specific Piagetian tasks. It consists of 36 open-ended items administered in a one-to-one situation. Subjects were middle to upper class, predominantly white elementary school students. The 168 students were randomly drawn from…

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…