Construct Validity and Factor Structure of the Persian Occupational Self-Assessment (OSA) With Iranian Students.

This study aimed to investigate construct validity and factor structure of the Persian Occupational Self-Assessment (OSA; Baron, Kielhofner, Iyenger, Goldhammer, & Wolenski, 2003 ) based on the model of human occupation (MOHO). Three hundred and thirty-six (179 male and 157 female) Iranian junior high students were measured using the OSA. The data were analyzed using a Confirmatory Factor Analysis (CFA) and the Rasch Rating Scale Model (RSM). In combination, the CFA and RSM results provided strong evidence for the construct validity of the Persian version. The CFA indicated that the hypothesized second-order model could explain the relationship of the OSA items to the latent variables of occupational competence and value for occupations. However, RSM item hierarchies did not replicate those found in previous international studies.