Autism Diagnostic Observation Schedule™ (ADOS)

The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a structured play and conversation session used to help diagnose autism. Rather than asking a parent to report, a trained clinician sets up standardized activities designed to create natural openings for social behavior, then observes and codes what the person does: how they communicate, interact, play, and whether restricted or repetitive behaviors appear.

Five modules cover roughly age 12 months through adulthood. A person is given only one, chosen by their chronological age and expressive language level rather than by diagnosis. Modules 1 through 4 compare algorithm scores against cutoffs yielding autism, autism spectrum, or non-spectrum; the Toddler Module gives ranges of concern instead. It informs a diagnosis rather than making one alone.

Licensing Notes: ADOS-2 is a trademarked, proprietary instrument published by Western Psychological Services. It is qualification-restricted: purchasers must meet WPS qualification requirements, and some distributors require proof of ADOS certification before sale.

Learn More: Module selection is by language level, not age. A Comparison Score places a child's symptom level against others with an ASD diagnosis of similar age and language ability.