Beyond competence: The significance of performance for conceptual development

Conceptual constraints must change with age if they are to account for children's acquisition of kinds of knowledge that do not fall within the initial constraints. A bi-directional relation between competence and performance is therefore hypothesized, such that cognitive competences not only guide performance but also are shaped by it. This hypothesis offers a solution to the difficulties that current competence models have in accounting for developmental change. Goals are proposed as a potential source of changing constraints because they change with age, they shape what children do, and they also influence what children learn from what they do. These ideas are illustrated with examples drawn primarily from research on children's quantitative concepts.