A functional (as opposed to structural) theory of intellectual development is presented and used to generate specific performance models for Piagetian tasks involving the control of variables (cf. Inhelder and Piaget, 1958). On the basis of these models, it is concluded that intelligent, field independent 7- and 8-year-olds should be able to…

Studied performance of 15 low-socio-economic-status 14 year olds in learning controlled-experiment design and evaluation, and indicated that experimental subjects significantly outperformed matched controls. (CC)