An examination of the structural validity of the Physical Self-Description Questionnaire-Short Form (PSDQ–S) using the Rasch Measurement Model

Abstract

It is important for self-report scales and measures used by educators and health care professionals (such as the Physical Self-Description Questionnaire-Short Form [PSDQ–S]) to have documented reliability and validity. The aim of this study is to investigate the structural validity of the full PSDQ–S composite scale and 11 subscales using the Rasch Measurement Model. 117 healthy children (65 males and 52 females; M = 10 years, 2 months, SD = 1 year, 4 months) completed the PSDQ–S. The PSDQ–S’s rating scale functioning, dimensionality, hierarchical ordering, differential item functioning (DIF), and item and person separation reliability were examined. Results supported the scale functioning, dimensionality, hierarchical ordering, DIF, and reliability of the PSDQ–S composite scale and each of its 11 subscales. Therefore, the PSDQ–S composite scale and 11 subscales can be used with confidence to assess children’s self-reported physical self-concept.