The Piagetian model of intelligence consists of the elements of content, mental structures and mental functioning. While the first two elements are said to be variants, the third element is described as invariant. Mental functioning begins with a process called assimilation which promotes disequilibrium and, in reestablishing equilibrium, the learner accommodates to what was assimilated. The assimilation-disequilibrium-accommodation process has been labeled adaptation which Piaget described as the accord of thought with things. The newly-acquired ideas (or concepts) are next organized with other knowledge; Piaget described that organization process as the accord of thought with thought.

While the Piagetian mental functioning model has been available for some time, empirical evidence that the model actually did or did not function was not found. Teaching and curriculum development procedures were extracted from the mental functioning model and a twelfth-grade physics course was so organized and taught. Naturalistic data collected from individual student interviews and in-class discussions were used to evaluate the hypothesis that mental functioning and the factors which compose it are integral parts of the learning process.