UC San Diego

The present research explored the effects of stimulus and task factors on preschoolers' (Exp. 1 and 3) and adults' (Exp. 2) tendency to categorize according to taxonomic relations, when those relations conflict with appearances. In Experiment 1, we examined the effects of and interactions among (a) available information, operationalized by using more- or less-informative stimulus types (objects vs. line drawings) and by the presence or absence of object labels, and (b) task constraints, operationalized by comparing sorting questions with inductive inference questions. When provided with information that constrained the categorization decision, either through labels or a combination of objects and inference questions, preschoolers based categorizations on taxonomic relations, not appearance. In Exp. 2, stimulus type (objects vs. drawings) were shown to have a similar effect on adults. In Exp. 3, we examined the effects of stimulus type on children's inductive inferences and naming accuracy. Effects in the two tasks were similar, suggesting that amount of stimulus information affects different judgments similarly. The findings show interactive and main effects of available information and task constraints on young children's categorization decisions.