A short and very short form of the physical self-inventory for adolescents: Development and factor validity

Abstract

Objectives The Physical Self-Inventory (PSI)—a French adaptation of the Fox and Corbin's [1989. The Physical Self-Perception Profile: Development and preliminary validation. Journal of Sport and Exercise Psychology, 11, 408–430] Physical Self-Perception Profile—was originally developed for use with adults and no study has systematically verified its psychometric properties in adolescent populations. Additionally, this instrument remains too long to be efficiently completed in combination with multiple other instruments within extensive longitudinal or idiographic studies. The purpose of the present investigation was thus threefold: (a) testing the factor validity and reliability of the original PSI in a sample of adolescents; (b) developing and testing the factor validity and reliability of a very short (i.e., two items per scale) form of the PSI in a sample of adolescents; and (c) testing the equivalence of the factor pattern, structural parameters, latent mean structure, and criterion-related validity of both forms of the PSI. Design Structural equation modeling approach. Method Two samples participated in this series of studies. In Study 1, a sample of 1018 adolescents completed the adult PSI (25 items) and was randomly split in two sub-samples. In Study 2, a new sample of 320 adolescents completed a very short form of the PSI (PSI-VSF). Factorial validity and gender and multigroup invariance of these instruments (PSI, PSI-VSF) were tested using confirmatory factorial analysis (CFA) and structural equation modeling (SEM). Results In Study 1, CFA and SEM analyses provided evidence for the factor validity and reliability of a short (PSI-SF: 18 items) and very short (PSI-VSF: 12 items) form of the PSI for adolescents. In Study 2, CFAs and SEMs supported the equivalence of the factor pattern, structural parameters, latent mean structure, and criterion-related validity of both forms of the PSI (i.e., PSI-SF, PSI-VSF). Conclusion The present results thus provide preliminary evidence regarding the reliability and validity of a short and a very short form of the PSI for French adolescents.