Overview

The Developmental, Diagnostic and Dimensional Interview (3di) is an innovative computerised assessment for autism spectrum disorder and other psychiatric disorders of childhood. The 3di includes the following features:

• a dimensional assessment of the severity of features associated with a diagnosis of autism

• allows an assessment for autism in as little as 45 minutes

• automatic production of comprehensive reports detailing information collected in the interview; the major reports are suitable for parents and referrers with limited editing

• excellent reliability and validity; criterion validity established in relation to the ADI-R for the ICD-10 ASD assessment

• high agreement with the ADI-R’s ASD algorithm

This online user guide covers modern versions of the 3di software from 2022 onwards. For older versions of the software, please consult the printed user guide provided during your training course, or the digital copy found in your 3di installation folder.