Individual Differences in Addition Strategy Choice: A Psychometric Evaluation

The strategy choice model (SCM) is a highly influential theory of human problem-solving. One strength of this theory is the allowance for both item and person variance to contribute to problem-solving outcomes, but this central tenet of the model has not been empirically tested. Explanatory item response theory (EIRT) provides an ideal approach to testing this core feature of SCM, as it allows for simultaneous estimation of both item and person effects on problem-solving outcomes. We used EIRT to test and confirm this central tenet of the SCM for adolescents' (n = 376) solving of addition problems. The approach also allowed us to identify the strategy choices of adolescents who still struggle with basic arithmetic. The synthesis of SCM theory and EIRT modeling has implications for more fully investigating the sources of individual differences in students' problem solving, and for identifying problem-solving patterns associated with poor academic achievement. Educational Impact and Implications Statement Strategy usage may be an important avenue for the identification and treatment of mathematics difficulties. The current study examined individual differences in strategic problem-solving behavior with a sample of adolescent problem-solvers. Results indicate that even in adolescence there are meaningful individual differences in how students solve addition problems, including some adolescents who continue to rely on immature counting strategies. Those adolescents who still relied on immature counting strategies were also struggling with broad mathematical achievement. These struggling students can be identified with a brief addition strategy assessment, and our results suggest that they may benefit from mastering more developmentally mature strategies. For students with mathematical difficulties, simply advancing to developmentally mature strategy selection may be an important intervention goal, one which is often overlooked in educational settings.