Pyramid USA Clinical Director, Catherine Horton, MS, CCC-SLP, BCBA gives insight into how PECS is evidence-based and the research behind the 6-phase protocol.

Practitioners and caregivers often have questions about the available literature related to the PECS Protocol.  As of January 2023, there are nearly 250 PECS-related publications.  For the most up-to-date list, please refer to our Research Tab.  Through accessing the link, you will find that there are articles from countries around the globe relating to a variety of different topics.  You can sort the literature to view articles of interest. We encourage readers to review the original articles whenever possible, as there continues to be misinformation related to PECS that simply appears in-print (social media, articles and even blogs) versus the inclusion of Randomized Controlled Trial (RCT) studies (gold standard of research) that can be accessed via the link above.  The remainder of this blog will focus on four seminal articles that are frequently cited and/or have been most impactful on understanding the outcomes of PECS implementation.

Dr. Andy Bondy and Lori Frost first described the PECS Protocol and associated outcomes in an article highlighted in Focus on Autism in 1994.  This publication has over 2,000 citations and includes the first published description of the six phases of the PECS Protocol as implemented within a public-school setting.  Initial outcomes were also reported, including the large number of preschool aged children that had transitioned from PECS to using speech as their primary means of communication.

Another important article by Charlop-Christy and colleagues appeared in the Journal of Applied Behavior Analysis in 2002.  This article is also frequently cited with over 1,000 citations.  The study included three children with an autism diagnosis and used a multiple baseline design.  Outcomes demonstrated that not only was PECS an effective communication protocol, learners also increased the number of spoken words and decreased challenging behaviors – two very important “side effects” of PECS implementation that have been frequently cited in publications appearing after this initial article.

Several available articles compare the PECS Protocol with other approaches, including the RCT published by Schreibman & Stahmer in 2014.  Interestingly, the article compared the effects of Pivotal Response Training (PRT), as developed by the authors of this study, with PECS.  Of note, PRT is a speech-based protocol based upon a behavioral model emphasizing a developmental approach and does not include use of visuals/pictures.  Thirty-nine young children were randomly assigned to either the PECS group or PRT group.  All participants had ten or fewer spoken words in their repertoire. Outcomes indicated that twelve of the nineteen participants in the PECS group mastered skills through commenting at Phase VI.  In addition, all nineteen participants mastered through Phase II, with eighteen learners mastering skills through picture discrimination at Phase III, in a relatively short timeframe.  Perhaps more importantly, in terms of speech acquisition, the groups did not significantly differ in terms of the number of spoken words. In other words, PECS users developed the same number of spoken words as the PRT group. In fact, children in the PECS group averaged almost 90 spoken words at six months and 120 spoken words at the three-month follow up.  For the learners that did not go on to develop speech, following completion of the study, all PECS learners demonstrated preliminary functional communication skills.  In contrast, leaners in the PRT group left the study demonstrating no universal means of communication.

Last, but certainly not least, intervention for children with ASD has long been a concern for medical professionals.  In 2012, Maglione and colleagues published a set of guidelines in the journal Pediatrics regarding nonmedical interventions in ASD. Within those guidelines, it was noted, “Individuals with ASDs who have limited verbal language, or those who do not respond to multiple interventions aimed at improving communication, should be offered the opportunity to use the PECS.”

The first publication related to the efficacy of the PECS Protocol appeared in the literature nearly thirty years ago.  A simple online search of the term “PECS” yields over 59,000,000 results pointing to the popularity of the approach.  The research, specifically including the gold-standard RCT studies, indicates not only the effectiveness of the approach but also socially-significant gains in related areas such as speech development.  We continue to look forward to the ever-growing body of research celebrating the time-tested effectiveness of the PECS Protocol.


Bondy, A., & Frost, L. (1994). The picture exchange communication system. Focus on Autistic Behavior

Charlop-Christy, M. H., Carpenter, M., Le, L., LeBlanc, L. A., & Kellet, K. (2002). Using the picture exchange communication system (PECS) with children with autism: Assessment of PECS acquisition, speech, social-communicative behavior, and problem behavior. Journal of Applied Behavior Analysis, 35(3), 213–231

Maglione, M., Gans, D., Das, L., Timbie, J. & Kasari, C. (2012). Nonmedical interventions for children with ASD: Recommended guidelines and further research needs. Pediatrics, 130 (Supplement_2): S169–S178.

Schreibman, L. & Stahmer, A. (2014). A randomized trial comparison of the effects of verbal and pictorial naturalistic communication strategies on spoken language for young children with autism. Journal of Autism and Developmental Disorders44(5):1244-51



Additional Support

Looking for upcoming workshops? Visit our training schedule! We recommend our PECS Level 1 Training so you can see first-hand the 6-phase protocol backed by research.

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Written By Catherine Horton, MS, CCC-SLP, BCBA

© Pyramid Educational Consultants, LLC. 2023