The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a semistructured, standardized assessment commonly used to evaluate individuals referred for autism spectrum disorder (ASD) in clinical and research settings. It is a direct observational measure, providing a context in which the examiner can elicit and observe the symptoms associated with ASD. This entry describes the modules of the ADOS-2 and the reliability and validity of the assessment.

To be appropriate across a range of developmental and language levels, the ADOS-2 is composed of five modules, with the lower modules (Toddler, 1, and 2) being used for individuals who are nonverbal or have single-word and/or simple phrase speech, and the upper modules (3 and 4) being used for individuals with fluent speech. One module is selected for ...