Support for the operation of internal factors in cognitive development was provided by an obtained increase from first to second posttest scores. Two conservations were considered to be involved--conservation of the whole and of the part. (Author)

Three experiments explored effects of stimulus and task factors on tendency to categorize according to taxonomic relations when those relations conflict with appearances. When provided with information that constrained categorization, preschoolers and adults reliably based their decisions on taxonomic relations between physically dissimilar items.…

Two studies with 3-, 4-, and 5-year-olds examined whether young children can differentiate expertise in the minds of others. Findings indicated that all children could correctly attribute observable knowledge to familiar experts, such as a car mechanic. Preschoolers had difficulty making attribution of knowledge of scientific principles to…

Two experiments examined 4- to 5-year-olds' acquisition of family-resemblance categories for fictitious animals. Results showed that children who performed theory-guided learning were more successful at making feature/category associations than children who performed similarity-guided learning and categorized attributes significantly better than…

Four experiments investigated 3-year-olds' understanding of the differential importance of shape for categorizing solid objects. Found that they categorized rigid and deformable objects differently in a non-naming task and knew that material was important for deformable items and shape for rigid items. In two naming tasks, they generalized names…

Six match-to-sample picture/object selection experiments explored 3- to 5-year-olds' knowledge about superordinate words and acquisition of this knowledge. Findings indicated that number of standards (one versus two), types of standards (different versus same basic-level categories), and nature of representation (pictures versus objects)…

Examined preschoolers' ability to map novel adjectives to object properties in two experiments. Found that 4-year-olds could extend novel adjectives from target to matching test object whether objects were drawn from same, or different, basic level categories. If 3-year-olds' first extended a novel adjective to objects in the same basic level…

Examined degree to which analytic and holistic modes of processing play a role in children's and adults' categorization of faces. Found a developmental trend from analytic to holistic processing and an effect of face inversion with increasing age. Seven-year-olds processed faces comparably to nonfacial visual stimuli, whereas a growing proportion…

Two studies examined whether infants' category discrimination in an object-examination task was based solely on an ad hoc analysis of perceptual similarities among the experimental stimuli. Findings indicated that 10- to 11-month- olds' responses varied systematically only with the presence of a category change, but not with the degree of…

Three studies explored whether children's tendency to extend object names on the basis of sameness of shape (shape bias) is specific to naming. Findings indicated that 2- and 3-year-olds showed shape bias both when asked to extend a novel name and when asked to select an object of the same kind as a target object; 3-year-olds also showed shape…

Assessing Markman's hypothesis that the organizational principles underlying collection concepts facilitate children's performance on cognitive tasks requiring part-whole comparisons, three experiments indicated that the facilitative effect of collection labels appears to be specific to the class-inclusion task. Results suggest that Markman's…

Calls for a process-oriented approach to study of categorization in infancy. Maintains that further understanding of infant categorization and its changes with development requires a more direct assessment of infants' category formation. Argues that two research directions will enhance understanding of categorization: (1) contextual variations on…