The Quantitative Checklist for Autism in Toddlers (Q-CHAT) is a parent-report 25 item questionnaire that aims to capture traits that may be related to autism in toddlers aged 18 – 30 months. Items focus on social communication, repetitive and stereotyped behaviors, and sensory behaviors.
The PDD Behavior Inventory (PDDBI) is a rating scale filled out by caregivers or teachers that was designed to assess children having a Pervasive Developmental Disorder (PDD; autism, Asperger disorder, PDD-NOS, or childhood disintegrative disorder).
The Childhood Autism Spectrum Test or CAST (formerly the “Childhood Asperger’s Syndrome Test”) is a 39-item, yes or no evaluation aimed at parents. The questionnaire was developed by ARC (the Autism Research Centre) at the University of Cambridge, for assessing the severity of autism spectrum symptoms in children.