Validity of the Asperger syndrome Diagnostic Scale

Until publication of the Asperger Syndrome Diagnostic Scale (ASDS) in 2001, no standardized and nationally-normed instrument existed specifically for the purpose of diagnosing Asperger syndrome (AS) [Myles et al., 2001. Asperger Syndrome Diagnostic Scale ASDS), PRO-ED, Austin]. This study sought to augment the existing psychometric data on the ASDS through examination of its divergent, convergent, and discriminative validity. Measures of AS, autism, and social skills competence were administered to 76 children with AS, autism, intellectually gifted children, and a control group of typically developing children without AS or autism. Results supported the divergent and convergent validity of the ASDS. Discriminative validity was partially supported. The ASDS was the best discriminator between children with AS and those without AS. Diagnostic accuracy for those with AS and autism was enhanced when scores on the ASDS were combined with scores on the Gilliam Autism Rating Scale (GARS) and the Social Skills Rating System (SSRS). Findings are discussed relative to the debate over the external validity of AS and the resulting limitations on research in the area.