Differential Item Functioning in Subgroup Comparisons: The Case of Distributive Justice in Intercollegiate Athletics

Abstract

The main purpose of the current study was to highlight the need for analysis of differential functioning of items employed in inter-group comparisons in sport management studies. Toward this end a seven-item scale was proposed, based on well-established scales in the literature, for evaluating perceptions of distributive justice by coaches affiliated with different divisions of the National Collegiate Athletic Association (NCAA). Two hundred, eighty-six coaches from Division I and 307 from Division III of the NCAA responded to the questionnaire. After carrying out the confirmatory factor analysis (CFA) for the measurement model, a differential item functioning (DIF) analysis was conducted. Results of the CFA showed that the model fits the data reasonably well for both divisions. However, the DIF analysis showed that five out of seven items performed (functioned) differently in the two groups. Results showed that beyond CFA, whenever a scale is proposed to compare groups, DIF analysis should be conducted in order to avoid misleading results due to biased items.