Psychometric properties of the Gilliam Autism Rating Scale–Third Edition (GARS-3) in individuals with autism: A pilot study

The purpose of this preliminary study was to study the psychometric properties of the Gilliam Autism Rating Scale-3 (GARS-3). Participants included children and adolescents diagnosed with autism who referred to autistic therapeutic centers in Tehran, of which 200 were selected (113 male and 87 female, mean of ages was 11.5 with SD=3.70), and we asked from their parents to complete GARS-3 and Child Behavior Checklist (CBCL). The results showed that internal consistency of GARS-3 was very good. Results also confirmed content, convergent and construct validity of the GARS-3. In general, results yielded that GARS-3 is a reliable and valid assessment tool to be used with individuals with autism