Autism Diagnostic Observation Schedule (ADOS-2)

The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a standardised, semi-structured observation used as one source of information in an autism assessment. Through activities or conversation suited to the person’s age and expressive language, a child psychologist trained in ADOS-2 observes social communication, interaction, play or imaginative use of materials where relevant, and restricted or repetitive behaviours.

ADOS-2 was developed for people from 12 months of age through adulthood. It is not an intelligence, academic achievement or language test, and it does not provide a stand-alone autism diagnosis.

What does ADOS-2 observe?

The activities give the child psychologist opportunities to observe behaviours relevant to the autism assessment question, including:

• how the child communicates and uses verbal or nonverbal social signals
• how they initiate, respond to and sustain social interaction
• play and imagination, when relevant to the selected module
• restricted or repetitive behaviours and interests that occur during the observation

ADOS-2 records behaviour observed in a structured setting at a particular point in time. It does not measure every aspect of a person’s communication, relationships or daily functioning.

Which ADOS-2 module is used?

ADOS-2 has five modules. The child psychologist administers one module selected according to chronological age and expressive language level, rather than choosing a module based on presumed autism severity:

• Toddler Module: for children aged 12 to 30 months who do not consistently use phrase speech.
• Module 1: for children aged 31 months and older who do not consistently use phrase speech.
• Module 2: for children of any age who use phrase speech but are not verbally fluent.
• Module 3: for verbally fluent children and young adolescents.
• Module 4: for verbally fluent older adolescents and adults.

The selected module determines the activities, questions and scoring approach used during the observation.

What happens during an ADOS-2 observation?

The person takes part in a series of structured social activities with the child psychologist. Depending on the module, these may involve play, looking at or discussing materials, storytelling or conversation. The child psychologist follows standard administration and coding procedures while observing how the person communicates, interacts and responds.

There are no school-style right or wrong answers. The purpose is to observe current behaviour in situations designed to create opportunities for social communication and interaction. The psychologist interprets what was observed in the context of the referral question and the person’s developmental and communication profile.

Can ADOS-2 diagnose autism?

ADOS-2 can contribute important observational information, but its score cannot confirm or rule out autism on its own. Australian guidance recommends that diagnostic decisions draw on multiple sources of information. Depending on the person and referral question, this may include developmental history, information from parents or carers and other people who know the person, clinical observation, everyday functioning and other relevant measures.

Results require clinical interpretation because behaviour can be influenced by language, development, anxiety, attention, the assessment context and other individual factors. ADOS-2 results also do not guarantee a diagnosis, NDIS access, funding, school adjustments, treatment or service eligibility.

How does ADOS-2 fit into an autism assessment?

A psychologist may select ADOS-2 when direct, standardised observation would help answer a broader assessment question. The observation should be considered alongside the person’s strengths, needs, history and functioning across everyday settings.

Learn more about Quirky Kid’s autism assessment service for children, or book an initial consultation to discuss the most appropriate next step for your child.