The Construction of a Newly Developed Measure of Vocational Skill of Store: Feasibility Study of Vocational Training through Virtual Reality with Head-Mounted Displays (HMD) for Students with Intellectual Disability (ID) in Senior High School

Independent employment for individuals with intellectual disabilities (ID) is crucial. Virtual reality technology (VRT) offers a controlled and safe training environment, and its psychometric properties need to be well-established if it is used as an educational tool. However, research on educational head-mounted displays (HMDs) as VRT tools for people with intellectual disabilities (ID) remains limited. This study evaluates (1) test-retest reliability, (2) criterion-related validity, and (3) known validity of a VR vocational program for students with ID. Method: A vocational skill-based virtual reality training (VRT) system utilizing a head-mounted display (HMD) was developed through the interdisciplinary collaboration of special education and information engineering experts. A feasibility study design was implemented with 37 technical high school students diagnosed with mild to moderate intellectual disabilities (ID). Social abilities were assessed via the Vineland Adaptive Behavior Scale, and cleaning proficiencies were evaluated using a VR-based "Windows Cleaning"and "Floor Cleaning"training module designed for vocational skills in a store environment. The test-retest reliability, criterion-related validity, and known-group validity of the developed VRT system were subsequently examined. Results: (1) The intraclass correlation coefficient (ICC) is 0.754, and the VR program showed good reliability. (2) A moderate correlation was found between the VRT task total time taken and the Vineland scale, and its criterion-related validity is good. (3) The VRT task total time taken is different between students with mild and moderate ID, and Known-group validity is acceptable. Conclusion: The VRT training program of vocational skills of stores demonstrates acceptable reliability and validity, supporting its use for improving cleaning skills in educational settings.