The Autism Diagnostic Observation Schedule, 2nd Edition (ADOS-2) workshop is designed for both clinicians and researchers with prior background in autism and formal testing methods. During this two-day clinical training, the ADOS-2 will be presented. The workshop will include seminar, video examples of modules, participant scoring and discussion. Participants must have access to an ADOS-2 manual and testing kit. Registration only available for Illinois clinicians. Protocol booklets for each module will be mailed to registered participants.