Rational skepticism: A scientific review of Witts' (2018) criticisms of the PEAK relational training system

Witts' (2018) review of the peer-reviewed research on the PEAK-Direct Training Module (Dixon, 2014) yielded a divergent conclusion from that of previous reviews (Reed & Luiselli, 2016; Dixon, Belisle, McKeel et al., 2017). Witts advocates for skepticism of this research due to methodological shortcomings, hyperclaiming of results, and inappropriate statistical testing procedures. We identified 30 criticisms in Witts' review, respond to each, and argue that all but 2 (7%) contain untrue assumptions (7, 23%), are not novel (5, 17%), are logically invalid (7, 23%), or are more appropriately framed as criticisms of applied behavior analytic research more generally (9, 30%). The two criticisms that support Witts' purpose in writing his review are minor and not fatal. We discuss all of Witts' criticisms both specifically and broadly to illustrate that most of his suggestions about applied behavior analytic research may actually serve to hinder progress in a discipline moving toward larger-scale research.

An external review of the conclusions regarding the peak direct training module

Promoting the Emergence of Advanced Knowledge-Direct Training Module (PEAK-DTM) is a commercially available assessment and curriculum for individuals whose language skills are not developmentally adequate. In their review of PEAK-DTM, Reed and Luiselli (2016) analyzed the extant literature on PEAK-DTM and concluded that it has a sound and growing body of empirical support on its efficacy, usability, and psychometric properties. Similar conclusions are mirrored in the PEAK-DTM literature and promotional material. I review these conclusions and contend that many overrate the research that backs them. Suggestions for a more rigorous research agenda on PEAK-DTM and its related modules are provided.

An Internal and Critical Review of the PEAK Relational Training System for Children with Autism and Related Intellectual Disabilities: 2014-2017

The PEAK Relational Training System was designed as an assessment instrument and treatment protocol for addressing language and cognitive deficits in children with autism. PEAK contains four comprehensive training modules: Direct Training and Generalization emphasize a contingency-based framework of language development, and Equivalence and Transformation emphasize an approach to language development consistent with Relational Frame Theory. The present paper provides a comprehensive and critical review of peer-reviewed publications based on the entirety PEAK system through April, 2017. We describe both psychometric and outcome research, and indicate both positive features and limitations of this body of work. Finally, we note several research and practice questions that remain to be answered with the PEAK curriculum as well as other many other autism assessment and treatment protocols that are rooted within the framework of applied behavior analysis.

Teaching complex verbal operants to children with autism and establishing generalization using the peak curriculum

The present study evaluated the feasibility of the PEAK Relational Training System's Generalization Module (Dixon, 2014b) to teach and establish generalization of autoclitic mands, distorted tacts, and creative path finding in three children diagnosed with autism spectrum disorder. Using a multiple-baseline design across behaviors, each participant was provided with differential reinforcement and a least-to-most prompting hierarchy for correct responses to a subset of stimuli, and responses to other similar stimulus sets were probed for emergent generalization. Following training, each participant successfully acquired the directly trained behaviors and demonstrated generalization to the nonreinforced test exemplars. These data support the utility of Skinner's (1957) analysis to teach complex forms of verbal operants, and suggest that a manualized curriculum such as PEAK may have utility for promoting skill development and generalization for front line staff and caregivers of children with autism.