Autism 1 –10 © The Author(s) 2014 Reprints and permissions:

aut.sagepub.com Measurement of intelligence in individuals with autism spectrum disorder (ASD) is integral to both clinical prac-tice and research. Diagnostic decision-making, treatment planning, research design, and neurodevelopmental theory in ASD all rely on intelligence test scores. Despite wide-spread use of intelligence tests in this population, there are still many unanswered questions about how to reliably assess this construct in ASD. Children with ASD can strug-gle in testing situations and core symptoms of the disorder may interfere with test reliability. The social, communica-tion, and behavioral difficulties inherent to ASD may dif-ferentially affect performance across measures. The present methodological study focused on how two widely used intelligence measures compare in characterizing the intelligence of adolescents with ASD. Assessment of individuals with ASD often includes, as a core component, measurement of an individual’s overall intellectual functioning. One major purpose of this intelligence assessment is to determine whether individuals meet the ASD diagnostic criterion that requires social com-munication impairments to be below what is expected given the individual’s cognitive/developmental level (American Psychiatric Association, 2013). Intelligence test scores are also administered to assess possible intellectual disability (ID), which is present in an estimated 55%–70 % of indi-viduals with ASD (Fombonne, 2005). A comparison of WISC-IV and SB-5 intelligence scores in adolescents with autism spectrum disorde