Toward a Behavior Analysis of Complex Language for Children with Autism: Evaluating the Relationship between PEAK and the VB-MAPP


The purpose of the present study was to evaluate the relationship between two behavioral language assessments that are currently used to evaluate the verbal repertoires of individuals with autism. The assessments include Promoting the Emergence of Advanced Knowledge Relational Training System (PEAK) and the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP). Forty students with autism were administered each of the assessments. The results suggest that there was a strong correlation between PEAK total scores and the VB-MAPP (r = 0.8266, p < 0.0001), and that a logarithmic regression model provided a good fit for the data (R = 0.9598). Also, a ceiling effect was observed for the VB-MAPP around a PEAK total score of 138 of 368, suggesting that PEAK may provide a more robust measure of advanced language skills in individuals with autism. The utility of these findings for behavioral clinicians and researchers are discussed. 2

Document Type





Autism, Complex verbal behavior, Language, PEAK, VB-MAPP

Publication Date


Journal Title

Journal of Developmental and Physical Disabilities