Infants' understanding of "toy model-real exemplar" relations was assessed through preferential looking and habituation tasks. Results from the preferential looking task suggest that 18-month toddlers are just beginning to demonstrate comprehension of symbolic relations between iconic models and their real object counterparts. Performance of 10-…

The retention of the conditioned response was tested in a retroactive interference paradigm. Results suggested that what is learned by children in simple conditioning paradigms is different than what is learned by adults in the same paradigms. (Author/PN)

This paper discusses research exploring the performance factors involved in studies which test for formal operations. It is suggested that several previous studies dealing with formal operations confound performance and competence in determining the extent of subjects' formal operations schemata. Factors which might account for performance…

The Conceptual Learning and Development (CLD) Model specifies four levels of concept attainment (concrete, identity, classificatory, and formal) and three uses of concepts (problem solving, subordinate-supraordinate, and principles). Longitudinal and cross-sectional studies of concept attainment may be conducted. The results of this study of 300…