Reviews "Levels of Cognitive Development," which presents a theory of cognitive development integrating discrimination- learning research with understanding of higher cognitive processes. Argues that strengths include its presentation of systematic research and providing continuity between past and present models. Weaknesses include…

Infants in four age groups--three, six, nine and twelve months--were exposed to an experimental procedure designed to assess the extent to which such subjects were capable of discriminating between different orientations of the same form, and the extent to which they were capable of recognizing the identity between different orientations of the…

Reports the results of two experiments dealing with children's visual and tactual performance. In the first task, after several presentations of a series, the tactual group made almost errorless discriminations. But with memory demands, tactual performance became poorer than visual performance. Found a large developmental difference. (JAC)

Simple and complex learning and problem solving situations were employed with mentally retarded children and adults. In the Rotation-Discrimination Complex and the Size-Discrimination Simple experiments, upper and lower test achievement subgroups were subjected to two basic types of visual discrimination at different levels of task complexity.…