The Autism Diagnostic Interview – Revised (ADI-R) assists with the diagnosis of autism in individuals of all ages. It also can be used to assess related disorders known as Autism Spectrum Disorders (ASDs). It is an extended interview that produces a range of information.

The ADI-R must be administered by an experienced interviewer who should be accompanied by a caregiver who knows the developmental history and the daily behavior of the patient. The individual being assessed is not present during the interview.

The assessed individual may be of any age as long as their mental abilities exceed two years and they may be from any setting. It takes between 1 ½ and 2 ½ hours to administer and score the ADI-R. The 85-page ADI-R Interview Protocol booklet has ninety-three items and is used by the interviewer to record responses.


Scoring of the ADI-R uses the Comprehensive Algorithm Form. Each algorithm is contained in a convenient form with codings from as many as forty-two of the basic interview items. Each algorithm is scored separately and then systematically combined into an interpretable result.

The Diagnostic Algorithm is used if the purpose of the interview is autism diagnosis. The Current Behavior Algorithm is used if the purpose of the interview is treatment or educational planning. If the purpose is for both diagnosis and treatment, a combination of both algorithms can be used.

Interview Protocol

The focus of the interview is on the following three domains of functioning: language and communication; restricted, repetitive, and stereotyped behaviors and interests; and reciprocal social interactions.

Administration procedures are standardized to ensure systematic and detailed descriptions of behavior. All needed background information and specific content structure is detailed in the manual so professionals with previous experience and training can work with the individuals.

Interviewers conducting the interview sessions must have extensive training and verification of coding and administration accuracy.


The Diagnostic Algorithm of the ADI-R is the primary application and focuses on the developmental history of the individual. This approach is fully researched and validated and is integral to the diagnosis of the assessed individual.

The Current Behavior Algorithm is a secondary application where scores are based on observed behavior in recent months. It is less formal and does not include a full developmental history, but it can uncover various areas of functioning and can be useful in providing a comparative basis for evaluation and treatment planning.

The ADI-R Algorithm result is different from a true clinical diagnosis. A clinical diagnosis comes from a licensed psychologist or physician, and is based on direct observations as well as information from multiple sources.

While the ADI-R result is not a full clinical diagnosis, it is a comprehensive mechanical result of coded information. It serves as a good check of the clinical diagnosis and contains validated clinical information by itself. It may also be useful as an aid in deciding if a full clinical assessment is warranted.

There are no scales involved in the scoring of the ADI-R because it lacks a test portion. It is strictly an interview that focuses on behaviors that don’t often occur in non-affected individuals. There are no norms, but rather categorical results. The accuracy of the results is evaluated with statistical methods and research.