The Autism Diagnostic Observation Schedule (ADOS) is a diagnostic tool that helps to identify autism and its severity. ADOS-2 (Autism Diagnostic Observation Schedule, Second Edition, 2012). It is a semi-structured, standardized assessment of social behavior for individuals with suspected autism spectrum disorders. The ADOS2 methodology can be used from the age of 12 months. A standardized 4-module toolkit is used depending on the child’s verbal abilities. The first module covers the pre-verbal (single) word stage (12-30 months), the second covers the pre-verbal (single) word stage (from 31 months), the third covers phrasal language, and the fourth covers fluent language (for children and adolescents). Each module contains standardized activities designed to highlight behavioral features appropriate to the chronological age of the person being assessed and to the age of psychological and linguistic development. The module to be used must be chosen before the assessment. To assess the behavioral characteristics of the subject more objectively, the professional may use more than one module.