Development, validation, and reliability of the Irrational Beliefs Scale for Sports Officials (IBSSO).

Application of Rational-Emotive Behavior Therapy (REBT) within performance environments is increasing, however measures that assess irrational beliefs in specific populations are encouraged. A population that may benefit from REBT is sports officials. This paper reports the development, validation and reliability of the Irrational Beliefs Scale for Sports Officials (IBSSO). Item development was drawn from original items of the Irrational Performance Beliefs Inventory (iPBI), then refined over three stages using an expert panel, novice panel and industry panel. Officials ( 402; 349 male, 50 female, 3 undisclosed) from 11 sports ( years' experience = 13.02; 10.24) completed the inventory, with exploratory factor analysis suggesting a 3, 4, and 5-factor model from 22 remaining items. A new sample of 154 officials (140 male, 12 female, 2 undisclosed) representing 9 sports ( years' experience = 14.61,  = 11.96) completed the IBSSO, along with 6 other related measures (e.g., Automatic Thoughts Questionnaire, Affective Reactivity Index) to assess criterion validity. A four-factor model showed acceptable fit, with self-depreciation, peer rejection demands, emotional control demands, and approval identified as subscales, as well as a three-factor model. The IBSSO was positively correlated with the additional measures and negatively correlated with age, demonstrating concurrent validity. To assess convergent validity, 94 new officials (83 male, 10 female, 1 undisclosed; 36.74 years,  = 15.03) completed the IBSSO and iPBI simultaneously. The IBSSO was positively correlated with the iPBI, indicating convergent validity. Furthermore, 29 officials (25 male, 4 female, years' experience = 14.57,  = 12.44) completed the IBSSO over three-time points, with a repeated-measures MANCOVA and Intra-Class Coefficients confirming test-retest reliability. The 16-item four-factor model was accepted based on statistical and theoretical fit. The paper presents a measure of irrational beliefs in sports officials, with investigation into the effectiveness of REBT with this population recommended. [Abstract copyright: Copyright © 2025 Carrington, Turner, North and Brady.]