Detection of cognitive structure with protocol data: Predicting performance on physics transfer problems

Abstract

This article presents a cognitive map proposed to be associated with understanding of the “system concept,” one component of the physics principle of Newton's second law. A definition of the concept is followed by the results of a problem-solving experiment designed to investigate whether or not good problem solvers possess cognitive structures similar to the one proposed. Think-aloud protocols were collected as subjects solved a series of physics problems involving Newton's second law. Coding schemes were used to analyze these protocols and to develop a quantitative index intended to reflect the extent to which subjects possessed certain components of the proposed structure. This index proved a highly significant predictor of performance on Newton's second law transfer problems contained in a written exam. In contrast, performance on a set of familiar problems in the same written exam was not a good predictor of performance on transfer problems. These results indicate that cognitive structures that connect the equation ΣF=ma and the concept of choosing appropriate systems are at least part of what constitutes understanding of the principle of Newton's second law. Implications for physics education and problem-solving research are presented.