Date of Award


Degree Name

Master of Science


Behavior Analysis and Therapy

First Advisor

Dixon, Mark


During the past decade, the prevalence of any developmental disability has increased from 12.84% to 15.04% (Boyle et al., 2011). In particular, the current rate of autism spectrum disorder (ASD) is estimated to effect 1 in every 68 children, 1 in 42 boys and 1 in 189 girls (Interagency Autism Coordinating Committee & US Department of Health and Human Services, 2012). Given that the prevalence of autism and other related disorders continues to increase, the number of children diagnosed with ASD who will become adolescents and adults over the next few years is considerable. More intensive evaluations and services are needed to address this aging population. A multiple probe design was used in the current study to demonstrate the effectiveness of the PEAK Relational Training System (PEAK; Dixon, 2014) in development of language and cognition in adults with autism. Additionally, this study evaluated if generalized behavior change occurred for participants following the implementation of the PEAK Direct Training assessment. This study will measure the effectiveness of the PEAK Relational Training System by comparing assessment scores from the Vineland Adaptive Behavior Scale-II (Sparrow, Cicchetti, & Balla, 2005) and the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP; Sundberg, 2008). Results revealed that verbal repertoires and adaptive functioning levels for participants increased following the implementation of programs from the PEAK Direct Training Assessment. Generalizes behavior change was achieved for all three participants through the acquisition of new untrained skills. Overall, this study provides empirical support for the PEAK Relational Training System in the development of language and cognition for adults with autism.




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