Scale development for measuring junior high and high school students' enjoyment, benefit, and psychological barrier for exercise by item response theory

Abstract

Scales to measure ‘enjoyment’, ‘belief of benefit’, and ‘psychological barriers’ to exercise and sports of junior high and high school students were developed using the item response theory (IRT). The purpose of this study was to construct the item pools for the scales and to estimate their validity.Eight hundred and seventy junior high school students and 675 high school students participated in the study. They answered a questionnaire including items about exercise habits, stage of change for exercise, enjoyment, benefit, and psychological barriers. IRT parameters—discrimination power and difficulty level—were estimated using the graded response model of IRT, and characteristics of items were investigated. The developed item pools of the scales included items with diverse parameters; 31 items for enjoyment, 27 items for benefit, and 17 items for psychological barriers.In order to investigate the validity of the scales, means of scale score for subjects were compared between the group participating exercise or sports (exercise group) and the non-participating group (non-exercise group). The results showed significantly higher enjoyment and benefit (t-test; p<0.001), and lower psychological barriers (p<0.001) in exercise group. The one-way analysis of variance for the scale score was executed with the stage of change as the factor. The scale scores of all three scales were significantly related to the stage of change (ANOVA; p<0.001). Since the scales correlated with each together, a t-test between the exercise and non-exercise group was executed for the original factor of a scale (residual) while controlling the other two scale scores by multi-regression analysis. The significant differences between groups were observed for the enjoyment and psychological barrier scales. The results indicate the scales have concurrent validity.