Rasch Analysis of General Self-Efficacy Among Individuals with Intellectual Disabilities

The self-efficacy of individuals with intellectual disabilities is considered an important factor in the psychological adjustment process. The General Self-Efficacy Scale (GSES) is commonly used to measure self-efficacy. However, previous studies have not examined the psychometric properties of the GSES among individuals with intellectual disabilities. Therefore, this study investigated the psychometric properties of the GSES using the Rasch model based on the item response theory. This study used secondary data from the Employment Panel Survey of Persons with Disabilities provided by the Republic of Korea Employment Agency for Persons with Disabilities. The panel survey collected data from individuals with intellectual disabilities in the Republic of Korea using the GSES. This study analyzed data from 232 individuals to determine GSES item fitness, item difficulty, rating scale fit, and reliability. The results revealed that eight of ten GSES items exhibited appropriate fit. Item difficulty required modification, indicating the need for items with lower difficulty. The four-point Likert scale used for responses was appropriate. Person and item separation indices demonstrated good scale reliability. These findings suggest that the GSES is effective for measuring self-efficacy in people with intellectual disabilities; however, some adjustments, such as changes in difficulty level, are required.