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Autism Diagnostic Observation Schedule, Second Edition

  • Catherine Lord
  • Michael Rutter, MD
  • Pamela C DiLavore
  • Susan Risi
  • Katherine Gotham
  • Somer L Bishop
  • Rhiannon J Luyster
  • Whitney Guthrie
Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is used to assess and diagnose autism spectrum disorders across age, developmental level and language skills
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ADOS-2 Manual
9780749164034 Qualification Level B




Age range:
12 months to Adult
Qualification level:
Completion time:
40-60 minutes
Scoring options:

Product Details

ADOS-2 improves an instrument already viewed as "the gold standard" for observational assessment of autism spectrum disorder (ASD). It can be used to evaluate almost anyone suspected of having ASD from one-year-olds with no speech, to adults who are verbally fluent.

'Due to international shipping delays we currently expect shipping in 5-6 weeks.'


  • Updated protocols, revised algorithms, a new Comparison Score, and a Toddler Module
  • Provides a highly accurate picture of current symptoms, unaffected by language
  • Semi-structured, standardised assessment of communication, social interaction, play, and restricted and repetitive behaviours
  • Presents various activities that elicit behaviours directly related to a diagnosis of ASD
  • Essential addition to any hospital, clinic or school that serves individuals with developmental disorders


ADOS-2 includes five modules:

  • One module per individual, selected on the basis of his or her expressive language level and chronological age
  • Choose the module that's appropriate for the individual you're evaluating
  • Protocol Booklets structure the administration and guide you thorough coding and scoring

Modules 1 to 4:

  • Three classifications: Autism, Autism Spectrum, and Non-spectrum
  • In the Toddler Module, algorithms yield "ranges of concern" rather than classification scores
  • Administration and coding procedures for the ADOS-2 are functionally identical to those for the ADOS
  • Some codes have been expanded and several new codes have been added
  • Protocol Booklets significantly improved - they now provide clearer, more explicit administration and coding instructions
  • Algorithms for Modules 1 to 3 have been revised to achieve more accurate and useful results
  • Updated algorithms provide a more uniform basis for comparing results across the three modules that are used with children and young adolescents
  • Comparison Score for Modules 1 to 3 allows you to compare a child's overall level of autism spectrum-related symptoms to that of children diagnosed with ASD who are the same age and have similar language skills
  • Score also makes it easier to monitor an individual's symptoms over time

Toddler module:

  • Designed specifically for children between 12 and 30 months of age who do not consistently use phrase speech
  • Existing ADOS-2 components have been revised, and new components added, to more accurately identify toddlers at risk for ASD
  • Algorithms provide "ranges of concern" rather than cutoff scores
  • Ranges help you form clinical impressions, but they avoid formal classification, which may not be appropriate at such a young age




For information on our ADOS-2 workshops please visit the training page


System Requirements

  • ADOS-2 Software requires a PC with Windows 11, 10, 8, 7, Vista or XP.
  • CD-ROM drive and USB port required. 
  • ADOS-2 software is not Mac compatible at this time.


About the ADOS-2 Workshops

I only require selected ADOS-2 modules. Can I purchase the modules separately?

The ADOS-2 includes five modules. Modules cannot be purchased separately. Practitioners must be trained on each module fully and be able to utilise all materials fully. This is because practitioners often have to be able to switch and be flexible between module administrations as needed by the requirements of the client being assessed.

How does the ADOS-2 compare to the ADOS?

The ADOS-2 offers revised algorithms and a new Comparison Score for Modules 1 through 3, a new Toddler Module, and updated protocols with clearer administration and coding guidelines for all modules.

I own and I'm already trained in the ADOS. What do I need to do to upgrade to the ADOS-2?

Upgrading to the ADOS-2 is easy. If you already own an ADOS kit, you can purchase an ADOS-2 Upgrade Package (9780749164065 or 9780749164058). The materials in this package can be combined with the materials in your ADOS kit to make an ADOS-2 kit.

I am new to the ADOS-2. What do I need to get started?

First, you'll need to purchase an ADOS-2 kit. Visit the ADOS-2 page for full product information.

Next, you'll need to obtain training in order to become competent in using the ADOS-2. See the FAQ "What is required for someone to become competent in using the ADOS-2?" for more information."

What is required for someone to become competent in using the ADOS-2?

If you are an ADOS-2 user who has not previously been trained in the ADOS, you should do the following to obtain essential competence in the ADOS-2:

Make sure you have prior education, training, and experience that includes extensive exposure to autism spectrum disorders.

Study the ADOS-2 Manual.

Take a Pearson ADOS-2 Clinical Training Workshop or use the ADOS-2 DVD Training Kit (9780749164072). Both options offer training in all five ADOS-2 modules.

Practice using the ADOS-2 on cases that are not part of formal evaluations, and become completely confident that you are familiar with the assessment activities and can apply the coding categories accurately. If you have considerable experience in formal behavioural observation and individual test administration, you may reach this level in as few as 10 practice sessions (2 per module). Otherwise, you may need considerably more practice to obtain competence in administering and coding the ADOS-2.

If you are involved in formal research that may be published in peer-reviewed journals, you must also take a research training workshop, which is followed by exercises to establish item coding accuracy to a specific criterion. NB Pearson is not involved in research training workshops. Click for information on training opportunities.

If you are an ADOS-2 user who is already trained in the ADOS, you should do the following to obtain essential competence in the ADOS-2

Study the ADOS-2 Manual.

Use the Pearson DVD Training Upgrade Kit (9780749164089) to obtain additional training focused on the new Toddler Module.

Practice using the ADOS-2 on cases that are not part of formal evaluations and become completely familiar with the ADOS-2, including the updated administration, coding, and scoring guidelines and the new Toddler Module.

If you are involved in formal research that may be published in peer-reviewed journals, you must also take a research training workshop, which is followed by exercises to establish item coding accuracy to a specific criterion. NB Pearson is not involved in research training workshops. Click for training opportunities.

How does the 2 day workshop differ from the 5 day reliability training?

The 2 day clinical workshop includes training on all ADOS-2 modules and a level of pre and post course work which involves: viewing DVDs for all modules; understanding the coding notes provided for these recorded case studies; and additional post course work on the toddler module which is not covered in the 2 days. All pre and post course DVDs and scoring notes are provided. Less time is spent on coding accuracy and establishing reliability for coding, with emphasis on administration and understanding the nuances of the assessment.

Is the ADOS software MAC compatible?

The ADOS software only runs on all Windows operating systems at this time.


Booking an event

Can I provisionally reserve a place on an event?

No. Unfortunately, we can only accept firm bookings for our events.


Before the event

I'm joining the online workshop from overseas, is the training suitable for me?

These workshops are designed for both clinicians and researchers. For clinicians with a prior background in autism and formal testing with a professional qualification that includes a diagnostic remit, e.g. (in the UK) a practitioner psychologist (clinical, educational, forensic), paediatrician, child or adult psychiatrist or forensic psychiatrist this 2-day workshop is sufficient to support use of the ADOS-2 to inform the diagnosis of autism and autism spectrum disorders*.

Physicians, psychologists, occupational therapists, and speech-language pathologists will be better prepared to make educational placement decisions and evaluate programs after completing the workshop.

Individuals with less background in testing but who provide service for individuals and families affected by autism may take the workshop for informational purposes. For researchers, this workshop is prerequisite to more thorough training offered by the ADOS-2 authors and designed to achieve the high cross-site inter-rater reliability required in published research.

*A central principle of professional test use is that individuals should use only those tests for which they have the appropriate training and expertise. For overseas clinicians attending the workshop who are looking to use ADOS-2 to inform the diagnosis of autism and autism spectrum disorders, please ensure the workshop meets any local and/or national requirements/guidelines in your country.


Cancelling or amending your booking

What is your cancellation policy?

You may cancel within 10 working days from the date of your booking, unless the event falls within the same period. However, no refund will be made if you make a cancellation within 10 working days of the date of the training. Please make sure you notify us via email or using this online form.

Your request must include the contact details you provided as part of the purchase process. For full details of our cancellation policy, please read our terms and conditions.

How will you let me know if my event has been cancelled?

All our courses are subject to cancellation or amendment until 14 days before the scheduled date, but we'll give you adequate notice of any changes. These will come via email, but if any changes are made within five working days of your course starting, due to exceptional circumstances, we may contact you by phone also.

My event has been cancelled. Will it be rescheduled?

Wherever possible, Training from Pearson UK will look to reschedule an event that has been cancelled. The exception to this is where events are cancelled due to low delegate numbers.


After the event

Can I provide feedback on the event?

Your feedback is vital to improving our courses and making sure they’re helpful to your professional development. After the event, we’ll email you with an event feedback form that you can complete.

ADOS-2 - UK Independent ADOS trainers

You can find a list of UK Independent trainers on the right hand side of the Weill Cornell Medical College website. They have all been trained on ADOS by its author Cathy Lord.

The information listed is not approved by Pearson and is provided by the independent trainers. For details of courses run independently please contact the organisers directly.