Researched the possibility that four- to six-year-old children are competent and systematic classifiers, at least making classifications by overall similarity. In three experiments, young children classified various sets of multidimensional stimuli that could be organized into catagories by overall similarity or by diminsional attributes. Children…

Two studies explored the hypothesis that young children perceive integrally some stimuli that older children perceive separably. In both experiments, kindergarten, second- and fifth-grade children were required to classify sets of stimuli that varied in size and brightness. (SB)

The developmental trend from overall-similarity to dimensional-identity classifications is explained by a quantitative model. The model provides good qualitative fits to the extant data. Three experiments examining classifications in 120 2- to 8-year-olds and in 20 undergraduates support specific new claims of the model. (TJH)