The CASS is a 60-item, parent-as-respondent inventory designed to assess the variety of autistic symptoms in the Autistic Disorder Spectrum including Asperger's Disorder and High-Functioning Autism and to differentiate between autistic disorders and children with other types of behavior disorders not associated with the autistic spectrum. The CASS is aligned with the criteria for Autistic Disorder in DSM-IV-TR, and it also assesses autistic symptoms from the relevant literature. There are four basic categories of symptoms: impaired socialization, speech and language problems, nonverbal communication difficulties, and repetitive/stereotyped behaviors. One unique feature of the CASS is that it has been empirically demonstrated to be able to differentiate between autistic disorders and childhood/adolescent Schizoid Personality Disorder. Each of the 60 items is answered on a 4-point Likert-type scale ranging from 1 (strongly false), 2 (more false than true), 3 (more true than false), to 4 (strongly true). The CASS has been normed on and tested with hundreds of children and adolescents diagnosed in Autism Spectrum.