What is the Autism Diagnostic Observation Schedule (ADOS)?

Autism Diagnostic Observation Schedule (ADOS)

What is ADOS?  The Autism Diagnostic Observation Schedule (ADOS) second edition is published by Western Psychological Services.  It’s a standardized assessment that can help in the diagnosis of autism spectrum disorders across all:

  • ages
  • language skills
  • cultural backgrounds
  • developmental levels

The ADOS Autism Diagnostic Observation Scale is a standardized diagnostic assessment of social, imagination and communication skills of individuals who may have autism spectrum disorders (ASD).  It primarily focuses on social and communication deficits since those are the most notable indicators of ASD.  It can be used to assist in an ASD diagnosis and help rule our other developmental disorders.

The ADOS is not required in order to make a diagnosis of autism spectrum disorder.  The criteria for an autism diagnosis is clearly spelled out in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).  Psychologists and psychologists can make a clinical diagnosis using whatever tools they find appropriate.  The ADOS provides professionals with a standardized and systematic method for identifying whether a child might be on the autism spectrum.

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The ADOS is not the only standardized diagnostic test for diagnosing ASD.  Another popular ASD assessment tool, the Autism Diagnostic Interview-Revised (ADI-R), is also used by professionals.  Using the ADOS and another tool like the ADI-R together in the diagnostic process can strengthen the data and provide more confidence when diagnosing autism spectrum disorders.

What is the ADOS and How is it Used? 

What is the ADOS and How is it Used? 

What is an ADOS?  The autism diagnostic observation schedule second edition uses planned social situations to trigger target responses and interpersonal interactions. These communication opportunities are designed to elicit a wide range of verbal, physical, social and imaginative interchanges.  It can be used on a variety of people, from very young children to adults.

The ADOS autism diagnostic observation schedule is divided into four unique modules that each requiring 30 to 40 minutes to administer. The individual being tested is given one of the ADOS modules dependent on their:

  • age
  • functioning
  • language level

The Modules

What is the ADOS and How is it Used? 
  • Toddler Module for children 12 to 30 months who aren’t consistently using phrase speech
  • Module One is used for children who have limited speech
  • Module Two is for those who can speak, but are not verbally fluent
  • Module Three is used with verbally fluent children
  • Module Four is used with verbally fluent adolescents and adults.

The autism diagnostic observation schedule ADOS does not contain modules that address non-verbal adolescents and adults.

The ADOS uses standardized:

  • terms
  • materials
  • activities
  • activity introductions
  • hierarchical sequences of social activities

Module One

The first Module is for preverbal and non-verbal children.  It includes scenarios involving:

  • snacking
  • free play
  • routines with objects
  • response to name
  • response to joint attention
  • birthday parties
  • bubble play
  • functional imitation

The module requires the test administrator and child to move about the room.  The examiner focuses on the child’s ability to interact playfully with the toys and other items.  In Module One, an evaluator may observe the child playing with a doll.  They might observe whether the child imitates the behavior modeled by the evaluator or whether the child actively engages with the doll.

Module Two

Just as in Module One, this module requires the test administrator and child to move around their environment.  The second Module includes scenarios involving:

  • conversations
  • task demonstrations
  • picture descriptions
  • make-believe play
  • task construction
  • book reading

This Module is designed for individuals with phrase speech abilities.  While some of the activities are similar those in Module One, some of the tasks are more complicated.  An evaluator might ask the child to demonstrate how to wash their hands or brush their teeth.  The individual might be asked to assemble a puzzle while looking at a picture on the box.

Module Three

Module Three involves more conversation so most activities are completed at a table or desk.  The third Module uses some of the second Module activities, but also includes:

  • cartoons
  • conversation reporting
  • emotional analysis
  • social challenges
  • story creation

Module Three is for children and adolescents who are verbally fluent.

Module Four

The fourth Module is for verbally fluent adolescents and adults. It includes discussions of:

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  • stories
  • work
  • school
  • books
  • friendship
  • loneliness
  • relationships
  • future plans

How Does the Test Work?

The ADOS modules contain standardized scenarios that the examiner walks the participant through.  In

The Scoring

How Does the Test Work for ADOS?

Each module takes about 40 minutes to complete.  There are guidelines for selecting the most appropriate module.  There are also instructions for the administrating, scoring and interpreting of the results.  Ideally, only one module will be used. If the behavioral specialist or educational psychologist determines that a more or less advanced module is appropriate, more than one module may be used.

The individuals’ behaviors are coded using a zero to three point ranking system. A zero indicates normal behavior, a one indicates occasional abnormalities, a two indicates a definite difference and a three indicates abnormal functioning.  Scores are summed for two domain scores (Communication Domain and Social Interaction Domain) and a combined Communication and Social Interaction Domain.

Each Module has a set of behaviors to score.  In Module One and Module Two, these behaviors include:

  • Stereotyped/idiosyncratic words or phrases
  • Facial expressions directed to others
  • Imagination/functional play
  • Repetitive behaviors or interests
  • Negative behavior
  • Speech abnormalities

The ADOS classifications are based on categorized and coded behaviors that use a diagnostic algorithm based on the DSM-IV diagnostic criteria.  ADOS play activities and stereotyped behaviors are coded, but they are not included in the scoring algorithm because it is difficult to assess general characteristics in a limited period of time.

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Various studies and research have explored and examined the effectiveness of the ADOS for clinical practice. Most studies show a 70 to 80 percent agreement between ADOS classifications and diagnostic criteria in the Diagnostic and Statistical Manual (DSM-5). The Autism Diagnostic Observation Schedule is part of a comprehensive evaluation that includes assessing developmental history, interviews with parents, and observations.  The Autistic Diagnostic Observation Schedule is being used to identify and manage children who have behavioral disorders and developmental challenges associated with autism.