Objective: To compare indirect and direct functional assessment of insistence on sameness associated with autism spectrum disorder (ASD) and typical development.
Methods: Parents rated the function of insistence on sameness for a 6-year-old boy with ASD (Peter) and a typically developing 4-year-old boy (Nathan) using the Motivation Assessment Scale (MAS). Ratings were compared to the results of a direct assessment.
Results: The results of the assessment procedures were mainly consistent for Peter and suggested that his tendency to insist on sameness was maintained by sensory consequences. The finding of an attention function for Nathan in the play-based assessment was consistent with previous functional assessment studies surrounding typically developing children, but in contrast to the MAS.
Conclusion: While the play-based assessment may be more suitable for assessing the high rate insistence on sameness observed in individuals with ASD, the MAS may be more suitable for low rate insistence on sameness.
Keywords: Autism spectrum disorder; functional assessment; insistence on sameness; play-based assessment; problem behaviour; typical development.