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)

This study illustrates the types of information microgenetic methods can yield. Ninety-seven 5-year olds who had not mastered number conservation were given training in conservation or in reasoning about conservation. Results elucidate how changes in thinking occur and demonstrate children's efforts to understand other people's reasoning. (SLD)

Three types of overgeneral uses of object names by young children were identified. Production data from 10 children were obtained using a standardized method of recording utterance contexts. Results showed that, like adults, children's object categories applied to objects of particular kinds. Most overgeneral uses were attributable to…

Seven experiments with a total of 423 three-five year olds assessed preschool children's ability to learn and transfer across problems that share a common underlying structure but differ in surface manifestations. Results are discussed in terms of explanation- or analysis-based models of both machine and human learning. (TJH)