Discusses metacognitive and associative models of children's strategy discovery and use. Contends that models based on only one type of mechanism cannot entirely account for observed variability and constraint revealed by microgenetic studies of children's strategy change. Proposes a new model of children's strategy development in which…

Discusses the problems of using chronometric analysis, a common cognitive psychological method, for educational assessment. Suggests that cognitive assessment has not reached the precision needed to analyze individual differences. (FMW)

Reviews evidence that children use diverse cognitive strategies; discusses the adaptive value of using diverse strategies; describes models of strategy choice based on rational calculations; and presents an overview of the distributions of associations model of children's strategy choice. (RH)

Analyzed 1.5- and 2.5-year-olds' problem solving and learning. Found that changes in toddlers' strategies could be assessed reliably on a trial-by-trial basis, that changes followed the basic form predicted by the overlapping waves model, and that analyses could reveal information about the qualitative and quantitative aspects of their learning.…