Autism Diagnostic Observation Schedule - Second Edition

The ADOS-2 provides a highly accurate picture of current symptoms, unaffected by language. It can be used to evaluate almost anyone suspected of having ASD—from 1-year-olds with no speech to adults who are verbally fluent.

The ADOS-2 is a semi-structured, standardized assessment of communication, social interaction, play, and restricted and repetitive behaviours. By observing and coding these behaviours, you can obtain information that informs diagnosis, intervention, treatment planning, and educational placement.

Test Components:

Five Modules

The ADOS-2 includes five modules, each requiring 40 to 60 minutes to administer. The individual being evaluated is administered only one module selected on the basis of his or her expressive language level and chronological age.

• Toddler Module—for children between 12 and 30 months of age who do not consistently use phrase speech
• Module 1—for children 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

Each module engages the examinee in a series of activities involving interactive stimulus materials (all included in the ADOS-2 Kit). To illustrate, activities in Module 3 are listed below:

• Construction Task
• Make-Believe Play
• Joint Interactive Play
• Demonstration Task
• Description of a Picture
• Telling a Story From a Book
• Cartoons
• Conversation and Reporting
• Emotions
• Social Difficulties and Annoyance
• Break
• Friends, Relationships, and Marriage
• Loneliness
• Creating a Story

Standardized Administration, Coding, and Scoring

Each ADOS-2 module has its own Protocol Booklet which structures the administration and guides you through coding and scoring. As activities are administered the examinee is observed, and behaviours are noted.   Immediately following administration, the behaviours observed are to be coded. The administrator then uses the algorithm form for scoring.

In Modules 1 through 4, algorithm scores are compared with cutoff scores to yield one of three classifications: autism, autism spectrum, or non-spectrum. The difference between autism and autism spectrum classifications is one of severity, with the former indicating more pronounced symptoms. In the Toddler Module, algorithms yield “ranges of concern” rather than classification scores.
Improved Protocol Booklets, Revised Algorithms, and a New Comparison Score

Administration and coding procedures for the ADOS-2 are functionally identical to those for the ADOS. Modules 1 through 4 retain the same basic activities and codes, though some codes have been expanded and several new codes have been added. Protocol Booklets for these modules have been significantly improved—they now provide clearer, more explicit administration and coding instructions.

Algorithms for Modules 1 through 3 have been revised to achieve more accurate and useful results and to provide a more uniform basis for comparing results across the three modules used with children and young adolescents.

A new Comparison Score for Modules 1 through 3 allows you to look at a child’s overall level of autism spectrum–related symptoms in relation to those of children diagnosed with ASD who are the same age and have similar language skills. This score also makes it easier to monitor an individual’s symptoms over time.

The New Toddler Module

The Toddler Module is designed specifically for children between 12 and 30 months of age who do not consistently use phrase speech. Observations are coded immediately following administration, and the codes are converted to algorithm scores. Toddler Module algorithms provide “ranges of concern” rather than cutoff scores. These ranges help form clinical impressions, but they avoid formal classification—which may not be appropriate at such a young age. The Toddler Module quantifies risk for ASD and provides guidance if continued monitoring is needed.

The Most Accurate Picture of Current ASD Symptoms

With improved algorithms, the ADOS-2 demonstrates strong predictive validity. It provides a highly accurate picture of current ASD-related symptoms, based on real-time observations. Physicians, clinical psychologists, school psychologists, speech–language pathologists, and occupational therapists can use ADOS-2 results to inform diagnosis, intervention, educational placement, and treatment planning. Because it can be used with a wide range of children and adults, the ADOS-2 is an essential addition to any hospital, clinic, or school that serves individuals with developmental disorders.