The Adaptive Behavior Assessment System (ABAS), developed by Patti Harrison and Thomas Oakland, is a comprehensive assessment tool used to measure adaptive behavior across the lifespan. The third edition of the ABAS was published in 2015. This entry first describes adaptive behavior and the ABAS, including the structure and administration of the measure. It then discusses the clinical uses and applications of the ABAS.

Adaptive behavior is the set of conceptual, social, and practical skills that people need in order to function in daily life. Adaptive behavior assessment is commonly used when evaluating individuals with intellectual or developmental disabilities. In fact, intellectual disabilities are, by definition, deficits in intellectual functioning and adaptive behavior. Adaptive behavior measures are also used to understand the daily living skills of ...