The ADOS-2 test, or the Autism Diagnostic Observation Schedule, Second Edition, is an activity-based assessment that a trained clinician uses to observe communication, social interaction, play, and repetitive behaviors associated with autism spectrum disorder (ASD). It is considered the gold standard for autism evaluation, and it’s one component of a comprehensive autism assessment.
If your child has been referred for ADOS-2 testing or you’re considering an evaluation, it’s natural to have questions about what the assessment involves. In this article, we’ll explain how the ADOS-2 is used to screen for autism, what clinicians look for during the evaluation, and how your family can proceed with ADOS-2 testing.
What Is the ADOS-2 Test?
The ADOS-2 is a standardized assessment that gives trained clinicians a structured way to observe behaviors associated with autism spectrum disorder (ASD).
During the evaluation, the clinician guides the individual through a series of age- and language-appropriate activities, conversations, or play-based tasks while observing how they communicate, interact socially, and respond to different situations.
The assessment typically takes 40 to 60 minutes and consists of one module that’s chosen based on the individual’s age and language abilities.
What ADOS-2 Stands For
ADOS-2 stands for Autism Diagnostic Observation Schedule, Second Edition. It was released in 2012 following decades of research since the original edition, and it includes major updates such as revised algorithms, expanded modules, and improvements that support more accurate evaluations.
Why It’s Called the Gold Standard
Autism can be challenging to diagnose since there are no biological markers and symptoms can vary among individuals with autism. There are several tools for autism assessment used by doctors, and the ADOS-2 is considered the gold standard because it has been widely researched and used for decades as one of the most accurate.
Originally developed by autism researcher Dr. Catherine Lord and her colleagues in 1989, the ADOS-2 has been refined over time to improve its accuracy and effectiveness across different ages and developmental levels.
What Does the ADOS-2 Test Measure?
The ADOS-2 evaluates behaviors commonly associated with autism. Children with autism typically show differences in the way that they communicate, interact with others, play, and respond to others, and the ADOS-2 assesses all these areas.
The Diagnostic and Statistical Manual of Mental Disorders divides diagnostic criteria for autism into two core areas. Accordingly, the ADOS-2 assesses behaviors related to each of these domains:
Communication and Social Interaction
The ADOS-2 autism test looks at how an individual communicates and connects with other people through play, conversation, and other activities. Depending on their age and language abilities, the clinician may observe:
- How they communicate with others
- Eye contact, facial expressions, gestures, and body language
- How they start or respond to social interactions
- Whether they share interests or try to get another person’s attention
- How they use verbal and nonverbal communication
Play and Repetitive Behaviors
Children with autism often exhibit certain responses and engagement styles during activities such as sensory-seeking, intense focus, or emotional regulation challenges. The ADOS-2 looks out for these differences in play, such as:
- Repetitive movements, speech, or use of objects
- Restricted or highly focused interests
- Sensory-related behaviors
- Responses to changes in activities or routines
- For younger children, how they engage in imaginative play and interact with toys
What Are the ADOS-2 Modules?
Because autism presents differently depending on the individual’s age and language abilities, the ADOS-2 consists of five different modules. The doctor, therapist, or other trained clinician who administers the test is responsible for choosing one module that’s most appropriate.
Modules for Toddlers and Young Children
The Toddler Module, Module 1, and Module 2 mostly use play-based activities to observe how children with minimal speech can communicate and interact with others. They also are designed to detect differences in play behaviors.
Modules for Verbally Fluent Teens and Adults
Module 3 and Module 4 are for children, adolescents, and adults who communicate fluently using full sentences. Instead of focusing primarily on play, these modules use conversations, storytelling, and social discussion tasks to observe communication and social understanding skills.
What Happens During an ADOS-2 Test?
During the ADOS-2 assessment, the clinician guides the individual through a series of standardized activities or casual conversations to observe natural behaviors like eye contact, gestures, and conversation style. Because the test is designed to evaluate real-life behaviors, it typically feels relaxed. For kids, it can even feel like playtime.
How the Test is Scored
Unlike a traditional test, there are no right or wrong answers in the ADOS-2. The clinician scores specific behaviors as they observe them during each activity. Most behaviors are rated on a scale from 0 to 3, and the scores are combined using the ADOS-2 scoring guidelines. The results help determine whether the individual’s behaviors are consistent with autism.
Many families receive feedback shortly after the evaluation, although the exact timeline varies depending on the clinician and whether additional assessments are being completed.
Can the ADOS-2 Be Done Online?
No, the ADOS-2 cannot be administered online because it relies on direct observation. While some parts of the evaluation, such as caregiver interviews or follow-up appointments, may be completed through telehealth, the ADOS-2 assessment itself is designed to be conducted face-to-face.
Does the ADOS-2 Diagnose Autism on Its Own?
The ADOS-2 is one of the most accurate tools for observing behaviors associated with autism, but it does not provide an autism diagnosis by itself. Clinicians use the ADOS-2 findings alongside other information to determine whether an individual meets the DSM-5 diagnostic criteria for autism spectrum disorder.
How Results Are Used Alongside Other Evaluations
The ADOS-2 is one part of a comprehensive autism evaluation. Psychologists and developmental pediatricians interpret the ADOS-2 results along with developmental history, caregiver interviews, medical information, and other assessments to make an accurate diagnosis.
Autism screening is routinely provided during 18- and 24-month well-child visits, which may lead to a referral for a comprehensive evaluation that includes the ADOS-2. However, evaluations can take place at any age if parents, caregivers, teachers, or healthcare providers have developmental concerns.
Getting Started With an ADOS-2 Test
The path to an autism diagnosis isn’t always easy, and we know how overwhelming it can feel to not have answers about your child’s development.
The ADOS-2 is just one part of a comprehensive autism assessment that helps healthcare providers to understand your child’s needs and connect them with the right services. If you have concerns about your child’s development, be sure to let your pediatrician know — they can assess your child and decide if an evaluation is warranted. If appropriate, the evaluation may involve ADOS-2 testing for autism and potentially a referral to services like early intervention ABA therapy.
For families exploring next steps after an evaluation, United Care ABA Therapy is here to help. We offer virtual therapy, in-home ABA therapy, and in-office sessions that are personalized to your child’s behavioral and developmental goals. We also partner closely with caregivers, providing parent resources and valuable guidance for promoting progress at home.
Contact us to learn more about United Care ABA therapy and how we support families throughout their journey.
ADOS-2 Test FAQs
What does the ADOS-2 test stand for?
ADOS-2 stands for Autism Diagnostic Observation Schedule, Second Edition. It’s a structured, activity-based assessment that clinicians use to observe behaviors linked to autism spectrum disorder in a natural, consistent way.
How is the ADOS-2 test scored?
A clinician rates specific behaviors on a scale, usually from 0 to 3, based on how typical or atypical they are for the person’s age and language level. These ratings are combined into an overall score using a standardized algorithm.
Can the ADOS-2 test be done online?
No. The ADOS-2 requires a trained examiner to be physically in the room with the person being assessed, since both need to interact closely with the same materials. It can’t be completed remotely or as a self-test.
What module is used for adults taking the ADOS-2?
Verbally fluent adults typically complete Module 4, which involves conversation about daily life, relationships, and hypothetical scenarios rather than play-based tasks.
Does the ADOS-2 test alone diagnose autism?
No. The ADOS-2 is one part of a full evaluation. Clinicians combine the results with developmental history, caregiver interviews, and other assessments before reaching a diagnosis.
