APA Dictionary of Psychology

a theoretical model that postulates the existence of multiple strategies of problem solving within a child’s cognitive repertoire and describes how use of these strategies changes over time. According to this model, strategies compete with one another for use: With time and experience, more efficient strategies are used more frequently, whereas less efficient strategies are used less frequently but never totally disappear. This contrasts with stage theory of strategy development, which postulates that more efficient strategies replace less efficient ones. Also called strategy choice model. [proposed by U.S. developmental psychologist Robert S. Siegler (1949–  ) and Christopher Shipley]