Test–Retest Reliability of the Persian Version of the Self-Determination Student Scale in Adolescents with Autism Spectrum Disorder

Abstract

Background: Adolescents with Autism Spectrum Disorder (ASD) may experience difficulties in social participation, executive functioning, independence, and transition to adulthood. Self-determination is an important construct for supporting autonomy and goal-directed behavior; however, the test–retest reliability of the Persian Self-Determination Student Scale (SDSS) has not been examined in adolescents with ASD.

Methods: This methodological reliability study included 19 Persian-speaking adolescents aged 13–18 years with Level 1 ASD recruited by convenience sampling from three rehabilitation and occupational therapy centers in Tehran. Participants completed the revised 88-item Persian SDSS twice with a 14-day interval. Test–retest reliability was assessed using single-measures Intraclass Correlation Coefficient (ICC) based on a two-way mixed-effects absolute-agreement model.

Results: All participants completed both administrations, and no missing responses were recorded. Scores ranged from 37 to 126 at the first administration and from 38 to 124 at retest. Mean SDSS scores were 101.26±23.00 and 100.84±22.87, respectively. The single-measures ICC was 0.998, with a 95% confidence interval of 0.996–1.000 (p<0.001).

Conclusion:  The revised Persian SDSS showed preliminary evidence of excellent test–retest reliability over a 14-day interval in this small sample of Persian-speaking adolescents with Level 1 ASD. Further studies with larger and more diverse samples are needed to examine additional psychometric properties.