The conceptual categories that children have developed in their second year were studied in five experiments using object manipulation tasks. Subjects included 152 children from 18 to 31 months of age. These very young children had formed global conceptions of many domains of objects. (SLD)

A seriation task (assembling a set of nesting cups) was used in this study to examine developmental changes in young children's ability to restructure a situation. Forty young children, eight each at 18, 24, 30, 36, and 40 months of age, participated in the study. Each child was presented with five nesting cups and was told he or she could play…

Five- to six-year-old children estimated the size of Euclidian objects using an addition rule of Height plus Width, rather than a multiplying rule. Within the framework of information integration theory, tested whether intensive handling of objects would facilitate shift from addition rule to multiplication rule. Found that following handling,…