Psychometric Properties of the Big Three Perfectionism Scale: Rasch Analysis

The Big Three Perfectionism Scale (BTPS) is one of commonly used measures for assessing individuals' perfectionism. The main purpose of this current study was to assess the psychometric properties of the Big Three Perfectionism Scale (BTPS) within the framework of the Rasch model. The sample consisted of 502 adolescents (53% males and 47% females). This study revealed were several important findings. First, adolescents interpreted the categories of the rating scales of the BTPS as intended and items demonstrated good targeting with the operating ranges from - 4.79 to 4.47 logits for rigid perfectionism, from - 3.84 to 3.76 logits for self-critical perfectionism and from - 4.04 to 3.92 logits for narcissistic perfectionism. Second, rigid perfectionism, self-critical perfectionism and narcissistic perfectionism exhibited unidimensionally, providing justification for the use of summed scores for each scale. Third, the average item difficulty of facets was different within each scale, with the facets of self-worth contingencies, socially prescribed perfectionism and other-oriented perfectionism being more difficult to endorse in their belonging scale. Fourth, there were no DIF items across sex, suggesting that items in three scales functioned equally across boys and girls. Fifth, rigid perfectionism (r = 0.15) and self-critical perfectionism (r = 0.55) were positively associated with neuroticism, but self-critical perfectionism (r = - 0.24) and narcissistic perfectionism (r = - 0.29) were negatively related with agreeableness. Finally, sex moderated the associations between rigid perfectionism and neuroticism. In sum, the findings in this study enhance psychometric properties of the BTPS.