A meta-analysis of single case research studies on aided augmentative and alternative communication systems with individuals with autism spectrum disorders.
PECS and speech-generating devices give the clearest communication boost among aided AAC tools for nonspeaking children with autism.
01Research in Context
What this study did
The team pooled 24 single-case studies on aided AAC for people with autism. They looked at PECS, speech-generating devices, and other picture systems.
All studies used single-case designs. Every participant had autism and little or no speech.
What they found
Large positive effects showed up across the board. PECS and speech-generating devices gave the biggest communication gains.
Skills beyond talking also improved, such as joint attention and reduced problem behavior.
How this fits with other research
Huang et al. (2026) now supersedes this work. Their meta of 37 Chinese RCTs found even larger gains with PECS, plus boosts in social and cognitive skills.
Cox et al. (2015) extends the story to tablets. They report tablets beat traditional PECS for speed of first words and child preference.
Johnson et al. (2021) adds a caution: AAC can spark more speech, but spoken output usually stays behind AAC use. The papers agree AAC works; they differ on how much natural speech follows.
Why it matters
If you have a nonspeaking learner with autism, start with PECS or an SGD. These two options have the thickest evidence base. Track both picture exchanges and spoken attempts so you catch any speech gains that pop up. When the child is comfortable, try a tablet app to see if faster progress or higher motivation appears.
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02At a glance
03Original abstract
Many individuals with autism cannot speak or cannot speak intelligibly. A variety of aided augmentative and alternative communication (AAC) approaches have been investigated. Most of the research on these approaches has been single-case research, with small numbers of participants. The purpose of this investigation was to meta-analyze the single case research on the use of aided AAC with individuals with autism spectrum disorders (ASD). Twenty-four single-case studies were analyzed via an effect size measure, the Improvement Rate Difference (IRD). Three research questions were investigated concerning the overall impact of AAC interventions on targeted behavioral outcomes, effects of AAC interventions on individual targeted behavioral outcomes, and effects of three types of AAC interventions. Results indicated that, overall, aided AAC interventions had large effects on targeted behavioral outcomes in individuals with ASD. AAC interventions had positive effects on all of the targeted behavioral outcome; however, effects were greater for communication skills than other categories of skills. Effects of the Picture Exchange Communication System and speech-generating devices were larger than those for other picture-based systems, though picture-based systems did have small effects.
Journal of autism and developmental disorders, 2012 · doi:10.1007/s10803-011-1212-2