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.

The present investigation sought to examine the efficacy of the instructional curriculum described in the Direct Training Module of the PEAK Relational Training System on the language repertoires, as measured by the PEAK direct assessment, of children diagnosed with autism or related developmental disabilities. Twenty-seven children diagnosed with pervasive developmental disorders were evaluated using the PEAK direct training assessment protocol prior to assignment to control and experimental groups. Participants in the experimental group received additional language instruction derived from the curriculum programs of the Direct Training Module, while participants in the control group received treatment as usual. Both groups were then re-assessed using the PEAK direct assessment after 1 month. A repeated measures ANOVA indicated that participants in the experimental group made significantly more gains in language skills than those who were assigned to the control group, F(1, 22) = 9.684, p = .005. Implications for evidence-based practice and future research are discussed.

The present study evaluated the effect of teaching nutritional information on the choice making of undergraduate students. The training procedure was based on the phenomenon of stimulus equivalence in order to create an efficient and effective method of teaching this type of information. Participants were asked to sort pictures of fast food items into categories of caloric content before and after they received relational training. Additionally, they were asked to select items they would like to eat immediately prior to and following the training procedure. Results indicated the number of items sorted correctly substantially increased for all participants and four of six participants made healthier choices following the intervention. Implications of teaching nutritional information as part of a behavioral model of weight loss treatment are discussed.

The present study evaluated the effectiveness of five packaged protocols from the Promoting the Emergence of Advanced Knowledge (PEAK) curriculum. The skills targeted in the study included complex verbal operants proposed by Skinner (Verbal behavior. Englewood Cliffs, NJ: Prentice Hall, 1957), an area that is lacking in the current literature. The target skills included autoclitics, metonymical tacts, tacting planet names, and guessing. The results suggest that the PEAK methodology was effective in teaching each of the targeted skills to a mastery criterion, as well as maintenance of those skills at a 2-week follow-up phase.

Two multiple baseline designs were conducted across participants to determine if the promoting the emergence of advanced knowledge (PEAK) equivalence module was an effective tool in teaching adults with autism relationships between stimuli. More specifically, a transitivity program utilizing the gustatory sensory modality was implemented. Stimuli were selected and probed initially preceding the training. First, gustatory stimuli to a visual picture were trained. Then, a visual picture to a spoken word was trained. Finally, once mastery criterion was reached, each participant's responding was tested to determine whether there were derived relations following training. Results showed that all three participants reached mastery criterion in training sessions and were able to derive new relations without direct training.