The development of children's rule use on the balance scale task.

Cognitive development can be characterized by a sequence of increasingly complex rules or strategies for solving problems, Our work focuses on the development of children's proportional reasoning, assessed by the balance scale task using Siegler's rule assessment methodology. We studied whether children use rules,, whether children of different ages use qualitatively different rules, and whether rules are used consistently. Nonverbal balance scale problems were administered to 905 participants between 5 and 19 years of age. Latent class analyses indicate that children use rules, that children of different ages use different rules, and that both consistent and inconsistent use of rules occurs. A model for the development of reasoning about the balance scale task is Proposed. The model is a restricted form of the overlapping waves model (Siegler, 1996) and predicts both discontinuous and gradual transitions between rules.