The use of rules on nonverbal balance scale problems was studied among 5- to 19-year-olds. Latent class analyses indicated that children used rules, that different rules were used by children of different ages, and that both consistent and inconsistent rule use occurred. A model for the development of reasoning about the balance scale task was…

Three samples of 8- to 16-year olds were assessed three times at yearly intervals on eight water-level items. Within-child change over age was viewed as stochastic process of the child changing or remaining in one of three latent strategy states. Although there was improvement in task performance over age, the general finding was that strategy…