Test sample selection by preschool children: honoring diversity.

In a test of an inductive inference, preschool children's selection of objects was examined. In Experiment 1, 4-year-olds selected diverse objects first in sequential selections; in Experiment 2, adults and 4-year-olds, but not 3-year-olds, made similar selections under the same conditions. A defective object led subjects in all age groups to test a similar object. In Experiment 3, 4-year-olds chose to test a pair of dissimilar objects rather than a pair of similar objects, but 3-year-olds did not. Three-year-olds' selections were independent of diversity. In Experiment 4, we attempted to emphasize the diversity of objects for 3-year-olds. Their first task was to select an object that was the same as or different from a target object. The subjects responded correctly in this task but did not prefer to test diverse objects. Experiment 5 showed that neither 3- nor 4-year-olds have a bias to select nondiverse objects in a nontest context. The findings indicate that children as young as 4 years old value diverse evidence in induction.