Enhancing Functional Communication Through the PECS Program for Children with Level 3 ASD

This study investigated the effectiveness of the Picture Exchange Communication System (PECS) as an alternative and augmentative communication (AAC) tool for children diagnosed with level 3 autism spectrum disorder (ASD), specifically focusing on those who are non-verbal or minimally verbal. It used a quantitative, quasi-experimental multiple baseline design involving four participants diagnosed with level 3 ASD, who were observed across three phases: Baseline A (pre-intervention), Baseline B (during intervention), and Baseline C (post-intervention/maintenance phase). Functional communication data was gathered through a structured Behavioral Observation Frequency Checklist in a real-world setting, conducted in a Special Education (SPED) school, supervised by a SPED teacher. The study analyzed using descriptive statistics, paired sample t-tests, and Cohen’s effect size to measure its impact and comparison of improvement across all phases. Results revealed significant improvements in functional communication scores from Baseline A (M = 77.8, SD = 17.2) to Baseline C (M = 99.5, SD = 11.9), t(3) = -3.84, p = .031, with a very large effect size (d = 1.92). While the difference between Baseline B and C was not statistically significant (p = .060), the effect size remained large (d = 1.48), indicating sustained progress. Phase 7 (generalization) demonstrated significant gains (p = .037, d = 1.79), confirming that PECS-trained behaviors transferred across settings and communication partners. These findings support and provide empirical evidence that PECS is an effective AAC tool intervention for enhancing functional communication. Specifically, PECS improved skills such as requesting desired items, expressing choices, and initiating interactions. Practical implications suggest that when PECS is incorporated into individualized education plans, it can be effectively integrated into daily classroom routines to support requesting, choice making, expression, and initiation of communication. This leads to increased classroom engagement, greater participation in academic and social activities, reduced frustration-related behaviors, and improved independence among learners with complex communication needs, including children with autism spectrum disorder. The integration of the Picture Exchange Communication System (PECS) into special education programs and recommendations for future research are discussed in the last section of the study.