cover-jcbs-2016Derived rule-following and transformations of stimulus function in a children’s game: An application of PEAK-E with children with developmental disabilities Journal of Contextual Behavioral Science.

Mark R. Dixon, Ryan C. Speelman, Kyle E Rowsey, Jordan Belisle

coverEstablishing derived categorical responding in children with disabilities using the PEAK-E curriculum Mark R. Dixon, Jordan Belisle, Caleb R. Stanley, Ryan C. Speelman, Kyle E. Rowsey, Dena Kime and Jacob H. Daar



Belisle, J., Dixon, M. R., Stanley, C. R., Munoz, B. and Daar, J. H. (2016), Teaching foundational perspective-taking skills to children with autism using the PEAK-T curriculum: single-reversal “I–You” deictic frames. Jnl of Applied Behav Analysis. doi: 10.1002/jaba.324

ABSTRACT: We taught basic perspective-taking tasks to 3 children with autism and evaluated their ability to derive mutually entailed single-reversal deictic relations of those newly established perspective-taking skills. Furthermore, we examined the possibility of transfers of perspective-taking function to novel untrained stimuli. The methods were taken from the PEAK-T training curriculum, and results yielded positive gains for all 3 children to learn basic perspective taking as well as for 2 of the 3 to derive untrained single-reversal I relations following direct training of single-reversal You relations. All participants demonstrated a transfer of stimulus function to untrained stimuli after the single-reversal deictic relations had been mastered.



Dixon, M.R., Belisle, J., Stanley, C.R., Daar, J.H., & Williams, L.A. (in press). Derived Equivalence Relations of Geometry Skills in Students with Autism: An Application of PEAK-E Curriculum. The Analysis of Verbal Behavior.


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Dixon, M. R., Stanley, C. R., Belisle, J., & Rowsey, K. E. (2016). The test-retest and interrater reliability of the Promoting the Emergence of Advanced Knowledge-Direct Training assessment for use with individuals with autism and related disabilities. Behavior Analysis: Research And Practice, 16(1), 34-40. doi:10.1037/bar0000027

ABSTRACT: The study evaluated the test-retest and inter-rater reliability of the PEAK-Direct Training (PEAK-DT) assessment. In the study, the reliability of PEAK-DT scores were assessed both in terms of raw scores and age referenced scores. To evaluate test-retest reliability, 39 participants with autism or a related disability were administered the PEAK-DT assessment on two occasions – during an initial assessment and a follow-up assessment after three-weeks to one-month. The results suggest that PEAK-DT had high test-retest reliability both for raw scores (ICC = .987, p < .001) and age referenced scores (ICC = .973, p < .001). In addition, 10 of the participants were assessed independently by two observers during the initial assessment period to evaluate inter-rater reliability. The results also suggested that PEAK-DT had strong inter-rater reliability (ƙ = .981, p < .001). Taken together, the results provide support for the reliability of PEAK-DT as a behavioral assessment of directly trained language skills.
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Belisle, J., Rowsey, K. E., & Dixon, M. R. (2016). The use of in situ behavioral skills training to improve staff implementation of the PEAK Relational Training System. Journal Of Organizational Behavior Management, 36(1), 71-79. doi:10.1080/01608061.2016.1152210

ABSTRACT: The study evaluated the effectiveness of an in-situ behavioral skills training (BST) program for training three direct-care staff to implement the Promoting the Emergence of Advanced Knowledge Relational Training System (PEAK) with three individuals with autism. PEAK is an evidence-based behavior analytic language development curriculum that uses discrete trials to promote the emergence of language. The data suggest that BST improved staff implementation of PEAK and resulted in a corresponding improvement in selected language skills across two of three learners with autism.

MA1_40617_Cover page 1.inddcKeel, A. N., Rowsey, K. E., Belisle, J., Dixon, M. R., & Szekely, S. (2015). Teaching complex verbal operants with the PEAK relational training system. Behavior Analysis In Practice, 8(2), 241-244. doi:10.1007/s40617-015-0067-y

ABSTRACT: The present study evaluated the effectiveness of five packaged protocols from thePromoting the Emergence of Advanced Knowledge (PEAK) curriculum.  The skills targeted in the study included complex verbal operants proposed by Skinner (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 two-week follow-up phase.


DaRASD One Wordar, J. H., Negrelli, S., & Dixon, M. R. (2015). Derived emergence of wh question–answers in children with autism. Research In Autism Spectrum Disorders, doi:10.1016/j.rasd.2015.06.004


ABSTRACT: Children with autism spectrum disorder often struggle to respond to conversational questions involving words such as “who,” “what,” and “where.” One reason for this may be that answering these types of questions requires a repertoire of relational responding in which the individual must select an answer based on the class memberships of stimuli found in the question. For example, answering the question, “Who do you see at the hospital?” requires identifying a potential response that is in coordination with both “who” and “hospital,” e.g., a doctor. The present study sought to examine this premise by providing training designed to promote relational responding to community associations, associations of noun types, and associations between wh– words and noun types. Three participants diagnosed with autism, between the ages of 10 and 12, were exposed to a multi-phase relational training sequence designed to establish equivalence class membership between community helper stimuli, noun-class stimuli, and wh– word relations using protocols from the PEAK Relational Training System (Dixon, 2015. PEAK relational training system: Equivalence module. Shawnee Scientific Press: Carbondale, IL; Dixon, in press. PEAK relational training system: Transformation module. Shawnee Scientific Press: Carbondale, IL). A concurrent multiple baseline across skills and participants design was used to evaluate the functional relationship between the establishment of these relations and the emergence of correct responding to wh– questions. Results indicated that for two of the three participants, mastery of these relations was functionally related to the emergence of accurate responding to untrained intraverbal wh– questions.


JOBERCTMcKeel, A.N., Dixon, M.R., Daar, J.H., Rowsey, K.E., & Szekely, S. (2015). Evaluating the efficacy of the PEAK Relational Training System using a randomized controlled trial of children with autism. Journal of Behavioral Education. doi 10.1007/s10864-015-9219-y


ABSTRACT: 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.

RASD One WordMcKeel, A., Dixon, M.R., Rowsey, K.E. & Daar, J.H. (2015). Correlation between PEAK Relational Training System and One-Word Picture Vocabulary Tests.  Research in Autism Spectrum Disorders.

ABSTRACT: The past few decades of research in autism spectrum disorders have been successful in developing effective behavioral treatments; however, the psychometrics of these strategies has not been documented well in applied settings.  The current experiment evaluated the relationship between established measures of language skills (Receptive and Expressive One-Word Picture Vocabulary Test; ROWPVT-4 and EOWPVT-4 respectively) and a recently released assessment and curriculum tool designed to teach instructional skills using a behavior analytic approach (Promoting the Emergence of Advanced Knowledge Relational Training System; PEAK).  Each participant was administered three assessments:  The PEAK Direct Training Module Assessment, the ROWPVT-4 assessment, and the EOWPVT-4 assessment.  Scores from all three assessments were compared to assess the relationship between each assessment.  The results indicated both a strong correlation between the PEAK Direct Training Module and commonly used language assessments (ROWPVT-4 and EOWPVT-4), as well as strong reliability in the administration of the assessments. 

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Dixon, M.R., Belisle, J., Stanley, C.R., Rowsey, K.E., Daar, J.H. & Szelkey, S. (2014). Toward a behavior analysis of complex language: Evaluating the Relationship between PEAK and the VB-MAPP. Journal of Developmental and Physical Disabilities. 15. doi: 10.1007/s10882-014-9410-4


ABSTRACT: 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 2  = 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.

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Rowsey, K. R., Belisle, J., & Dixon, M. R. (2014).  Principal component analysis of the PEAK relational training system.  Journal of Developmental and Physical Disabilities. doi: 10.1007/s10882-014-9398-9



ABSTRACT: The purpose of the present study was to examine the underlying factors within the Promoting the Emergence of Advanced Knowledge (PEAK) Relational Training System Direct Training Module.  Ninety-eight children with Autism or other developmental and intellectual disabilities were evaluated using the PEAK Direct Training Assessment, which endorsed the presence or absence of 184 possible skills within their repertoire.  Following this evaluation, a Principal Component Analysis was run which yielded a four-factor model of the PEAK Direct Training Module.  Specifically, factors that possessed Eigenvalues greater than three were retained.  Items were loaded onto each factor based on their correlation scores within a final rotated component structure matrix.  The resulting four-factor model includes the constructs of Foundational Learning Skills, Perceptual Learning Skills, Verbal Comprehension Skills, and Verbal Reasoning, Memory, and Mathematical Skills.  In an era of movement towards evidence-based practices, the present data provide support for PEAK system as a conceptually systematic approach to the treatment of children with autism.


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Dixon, M.R., Belisle, J., Whiting, S.W., & Rowsey, K.E. (2014). Normative sample of the PEAK relational training system: Direct training module and subsequent comparisons to individuals with autism. Research in Autism Spectrum Disorders. Volume 8, Issue 11, November 2014, Pages 1597–1606


ABSTRACT: The present data provide a normative sample of the PEAK: Direct Training Module Assessment and a subsequent comparison to individuals with autism. Altogether, 206 typically developing participants and 94 participants with autism took part in the study. For the normative sample, there was a strong relationship between PEAK total score and age (r = .659, < .01), and a cubic regression provided a strong fit for the data (R2 = .821, = 18.51, < .01).  The results from the autism sample suggest that there was not a significant correlation between PEAK total score and age (r = .021, p = .861), and that PEAK Total Scores for the autism group were significantly lower than the normative sample (t (275) = 10.63, p < .001). The data suggest that PEAK may be especially useful as an assessment and curriculum guide for individuals with autism, and future research should be conducted on the increasingly complex topographies of human language and cognition that PEAK affords clinicians.​

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Dixon, M.R., Whiting, S.W., Rowsey, K., Belisle, J. (2014) Assessing the Relationship between Intelligence and the PEAK Relational Training System. Research in Autism Spectrum Disorders. Volume 8, Issue 9, September 2014, Pages 1208–1213.

ABSTRACT:  The Promoting the Emergence of Advanced Knowledge (PEAK) Relational Training System is an assessment and curriculum tool developed for basic and advanced skills using behavior analytic approaches. The current study evaluated the relationship between intelligence (as measured by IQ scores) and performance on the PEAK assessment with children with autism or other developmental and intellectual disabilities. Each child was administered the PEAK assessment from the Direct Training Module. Scores from this assessment were compared to IQ scores for all participants to assess the relationship between the two measures. Results indicated a strong, significant correlation between scores on standardized IQ tests and scores on the PEAK assessment (r = .759, p < .01). The results demonstrated strong convergent validity and indicate that the PEAK may be a useful assessment and curriculum guide for training language and learning skills to individuals with autism and other developmental disabilities.

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Dixon, M. R., Carman, J., Tyler, P. A., Whiting, S. W., Enoch, M., & Daar, J. H. (2014). Peak relational training system for children with autism and developmental disabilities: Correlations with peabody picture vocabulary test and assessment reliability. Journal Of Developmental And Physical Disabilities, doi:10.1007/s10882-014-9384-2

ABSTRACT: The present investigation sought to explore initial psychometric properties of the PEAK Relational Training System – Volume 1: Direct Training for children with autism.  Thirteen children diagnosed with autism or related disorders were exposed to an initial assessment designed to evaluate skill deficits within their repertoire, the Peabody Picture Vocabulary Test, and the Illinois Early Learning Standards Test.  Additionally, staff performances were evaluated on reliability of delivery of the PEAK assessment.  Results yielded significant positive correlations among the obtained PEAK assessment scores, the Peabody and the Standards assessments.   Implications for evidence-based discrete trial training curricula are discussed.