printed by While teaching communication skills using high tech voice output devices may be possible, extensive experimental research has already produced solid evidence that PECS training results in swift increases in spontaneous and functional picture based communication in most children with autism and related developmental disabilities. (Pyramid Educational Consultants Inc. (2014). PECS® to SGD: Guidelines and recommendations for a successful transition. Retrieved from GuidelinesRecommendations-USA.pdf). When transitioning from one communication system to another communication system the new system must at least be as effective, if not more effective, than the initial system as determined through data collection and comparison. Children’s preference for mode of communication should be considered when designing and implementing communication interventions (van der Meer, L., Sutherland, D., O’Reilly, M., Lancioni, G., & Sigzfoos, J. (2012). A further comparison of manual signing, picture exchange, and speech-generating devices as communication modes for children with autism spectrum disorder. Research in Autism Spectrum Disorders, 6(4), pp doi: /j.rasd ) Subject: Thomas is an 18-year-old male with Autism Spectrum Disorder (ASD) and a developmental disability who lives at home with his parents and attends a special education classroom program within his local high school. Design: An A-B-A-B reversal design with a treatment comparison of PECS and Proloquo2Go on an iPad mini was used in order to assess most preferred and best outcome as a functional communication system. A brief consultation model was implemented over a four month period where the client’s mother, Patricia, acted as the main therapist (i.e., mediator model). Baseline: Baseline data was collected using the client’s current communication system, Proloquo2Go. Zero rates of manding were observed using the prescribed system over any of the three baseline sessions. Treatment: The intervention consisted of introducing the Picture Exchange Communication System (PECS TM ) following a manualized approach with direct training and coaching of the client’s mother, Patricia, on each phase and on daily data collection. Within a five week period, Thomas progressed from Phase I to a modified Phase IV (typical 2-word phrases e.g., verb + object, instead of using the [I want] icon). A total of three consults occurred during this time for training purposes and visual inspection of the data with observable client behaviour. * It should be noted that Thomas had a history with PECS prior to introduction of the iPad mini with Proloquo2Go. Client Preference Assessment/Treatment Comparison: Once Thomas acquired PECS to the same level of previously reported manding (e.g., phrase length requests using Proloquo2Go), client preference assessments were conducted. Three sessions occurred between November 7 th and November 28, 2014 in order to assess client preference between ProLoquo2Go and PECS. Generalization: PECS continues to be used as the main communication system within Thomas’ home environment. Weekly probe data is collected by the parent and shared with the Consultant. Efforts to generalize to school have not been successful as no professionals are trained in PECS in that environment. BACKGROUND PURPOSE AND HYPOTHESIS MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION ACKNOWLEDGEMENTS This case study shows that children’s preferences for a communication system should be considered when designing and implementing augmentative and alternative communication (AAC interventions). In any communication transition, the responsible team has an ethical responsibility to plan the transition in a manner that ensures that the individual does not lose any communication capabilities (Frost, L., & McGowan, J. (2011). Strategies for transitioning from PECS to SDG. Part 1: Overview and device selection. Perspectives on Augmentative and Alternative Communication, 20, pp doi: /aacc Generalizing PECS or any effective communication system for children with ASD is not possible when professionals working with that child (e.g., SLP and teachers) are not trained to mastery on these systems. Limitations: Some of the typical limitations encountered within mediator models such as precision of data collection, and absence of IOA data. However consultants directly observed Thomas and confirmed the data that was collected. The purpose of this case study was to increase functional communication through a treatment comparison of Proloquo2Go (on an iPad mini) and PECS in an 18-year-old male with Autism Spectrum Disorder (ASD). Proloquo2Go was previously introduced to the client while receiving IBI services approximately four years ago. A referral was made for behavior support. A functional analysis was conducted which indicated a tangible function. Proloquo2Go was not effective as a communication system in reducing the problem behaviour. These findings corroborate recent research which indicates that voice output devices or high tech speech generating devices (i.e., Proloquo2Go on an iPad) are not the modality of choice nor the most appropriate communication system for every non-vocal individual for ASD contrary to popular belief and media report. The results indicated that: 1) 1)The speech generating device did not result in spontaneous and functional communication 2) 2)PECS (a low tech selection based system) yielded significantly increased rates of manding 3) 3)Manding with PECS included varied and novel 2-word phrases with accuracy (i.e., correspondence checks at 80% or greater), which were acquired over a short period of time 4) 4)Social approach, eye contact, and a refined pointing response were corollary behaviours which were trained and quickly acquired during implementation of PECS 5) 5)Vocal behaviour emerged with PECS (i.e., some initial consonant phonemes emitted during PECS manding) 6) 6)Problem behaviour significantly decreased 7) 7)Social validity questionnaire indicated significantly high rates of satisfaction and benefit from a brief mediator model of treatment The authors would like to thank Thomas and, in particular, his mother, Patricia, for their willingness to be a part of our treatment team and for their hard work.