CATEGORIZATION OF ACADEMIC CONCEPTS AS A FUNCTION OF EXPERTISE

Abstract

While most previous studies have looked at expert-novice differences in conceptual structure in a wide variety of areas such as chess (de Groot, 1965; Chase and Simon, 1973) and physics (Chi et al., 1981), and have revealed interesting results, this study examined knowledge structure as a function of expertise in the domains of psychology and physics. There were three groups of subjects in each domain: Experts, Intermediates and Novices. Subjects in the Psychology domain were asked to sort 125 psychology concepts while Physics subjects sorted 97 concepts in physics. Clique optimization (Sriram, 1990; Sriram and Lewis, 1993) was used to reduce the composite sorts of each group to a hierarchical tree, from which the optimal level of partition was extracted and analysed. Differences in the bases of categorizations were evident in both domains: Experts tended to categorize concepts by their deep (semantic) features while Novices relied heavily on surface (orthographic) features of the concepts and Intermediates showed a mixture of both deep- and surface-feature processing. In addition to that, Intermediates and Novices with a higher Verbal Ability were closer to Experts in conceptual structure. However, there were also some differences between the two domains. In Psychology it was found that intragroup agreement on sorting increased with expertise, but in the case of Physics, Intermediates showed a consensus that was very similar to that of the Experts'. Expert-like conceptual structure predicted academic performance in Psychology Intermediates, but there was no such relation observed for Physics Intermediates. The changes that occur in knowledge structure during acquisition of expertise are discussed, together with the existence of a basic level of abstraction (Rosch et al., 1976) in these two domains. Finally, some implications of these results for education were suggested.