A Review of the Efficacy of the Picture Exchange Communication System InterventionAbstractIntroductionMethodSearch StrategyAnalysisInter-Rater ReliabilityResultsResearch DesignParticipantsInterobserver and Procedural ReliabilitySocial ValiditySettingsEfficacy and Effectiveness of PECSPre-Experimental StudiesSingle Subject StudiesQuasi-Experimental Group StudiesRCTsMaintenance and GeneralizationDiscussionConclusionAppendixReferencesORIGINAL PAPERA Review of the Efficacy of the Picture Exchange CommunicationSystem InterventionDeborah Preston Æ Mark CarterÓ Springer Science+Business Media, LLC 2009Abstract The Picture Exchange Communication System(PECS) is a communication program that has becomewidely used, especially with children with autism. Thispaper reports the results of a review of the empirical lit-erature on PECS. A descriptive review is provided of the27 studies identified, which included randomized con-trolled trials (RCTs), other group designs and single subjectstudies. For 10 appropriate single subject designs the per-centage of nonoverlapping data (PND) and percentageexceeding median (PEM) metrics were examined. Whilethere are few RCTs, on balance, available research pro-vides preliminary evidence that PECS is readily learned bymost participants and provides a means of communicationfor individuals with little or no functional speech. Verylimited data suggest some positive effect on both social-communicative and challenging behaviors, while effects onspeech development remain unclear. Directions for futureresearch are discussed including the priority need for fur-ther well-conducted RCTs.Keywords Picture exchange communication system Augmentative and alternative communication  AutismIntroductionSerious deficits in communication form part of the primarydiagnostic criteria for autism (American PsychiatricAssociation 2000). It has been estimated that aroundone-third to one-half of children and adults with autism donot have functional speech (Mirenda 2003). Such individ-uals may show only pre-intentional communication, suchas reaching for a desired item, or communication maydemonstrate intent through behaviors such as alternatingeye gaze, and conventional gestures such as pointing(Yoder et al. 2001). Communication may also take theform of challenging behaviors (Mirenda 1997). Whenspeech does develop it may be limited mainly to unusual orecholalic verbalizations (Paul 2005). Individuals withserious developmental disabilities other than autism mayalso fail to develop speech and language skills (Westlingand Fox 2004).In order to help develop communication skills, variousforms of augmentative and alternative communication(AAC) have been developed. These include the use ofmanual signs (e.g., Layton 1988; Yoder and Layton 1988),voice output communication devices (VOCAs) (reviewedby Lancioni et al. 2001), and various picture-based systems(Keen et al. 2001; Sigafoos et al. 1996). The PictureExchange Communication System (PECS) is a picture-based system developed by Bondy and Frost (1993, 1994)to help young children with autism acquire functionalcommunication skills. PECS appears promising for severalreasons. First, it avoids difficulties inherent in other sys-tems by requiring very few prerequisites; in fact the onlyprerequisite is that the individual can clearly indicate (e.g.,by reaching for an item) what he or she wants, in a way thatcan be shaped into exchanging a physical symbol such as apicture (Bondy and Frost 2002). Other skills such as eyecontact, motor or verbal imitation skills, the ability to sitquietly in a chair, match-to-sample skills, picture dis-crimination, or the ability to follow verbal prompts are notnecessary (Bondy and Frost 1994, 2002), at least at theearliest program stage.D. Preston  M. Carter (&)Macquarie University Special Education Centre, MacquarieUniversity, Sydney, NSW 2109, Australiae-mail: [email protected] Autism Dev DisordDOI 10.1007/s10803-009-0763-ySecond, the first skill taught in PECS is requesting.Requesting has often been targeted in early instruction ofindividuals with developmental disabilities due to moti-vational considerations (Reichle and Sigafoos 1991). Inrelation to PECS, it is argued that individuals with autismin particular are less likely to be motivated by the socialconsequences of labeling or commenting (Bondy and Frost1995) and more likely to be motivated by requesting andimmediately obtaining a specific, typically concrete,desired item (Bondy and Frost 1994). Third, PECS sys-tematically addresses the issue of spontaneity, which hasoften been reported as problematic in individuals withautism spectrum disorders (ASD) (Chiang and Carter 2008;Koegel 2000). Rather than being dependent on a partner toestablish a communicative exchange, or requiring a partnerto watch for the learner to point to a picture board orgenerate a manual sign, which could easily be missed,PECS specifically teaches the individual to approach thepartner and gain their attention by putting a picture symbolinto their hand. Fourth, picture symbols can be highlyiconic, closely resembling their referents (Ganz andSimpson 2004; Mirenda 2003). Consequently, they may beeasily recognized by the learner (Ganz and Simpson 2004)and are more recognizable by communicative partners thansome other systems, such as manual signs (Lancioni et al.2007).The PECS protocol begins with a reinforcer assessmentthrough which the trainer determines an ordered list ofreinforcers for the individual (Bondy and Frost 1998). Thisis followed by six phases, which are briefly overviewed inTable 1. For each phase, the criterion for successful com-pletion is 80% or more trials successful without promptingin a 10-trial block (Charlop-Christy and Jones 2006).The randomized control trial (RCT) is recognizedas providing the gold standard for evaluating clinicalinterventions in areas such as medicine and education(Evidence-Based Medicine Working Group 1992; WhatWorks Clearinghouse 2006) and ideally evaluations wouldbe limited to such evidence (Carter and Wheldall 2008).Such designs, however, are relatively rare in education-related areas (Carter and Wheldall 2008) for a variety ofreasons and clinicians must often look to a second line ofevidence to inform decision-making. Single subject quasi-experimental designs employ repeated measures of thedependent variable over time with a single or small numberof participants. Although not offering the standard of evi-dence of RCTs, the