Assessment & Research

Interaction of participant characteristics and type of AAC with individuals with ASD: a meta-analysis.

Ganz et al. (2014) · American journal on intellectual and developmental disabilities 2014
★ The Verdict

Match the device to the child’s profile: SGDs for autism-only, PECS for autism-plus-ID, and start young.

✓ Read this if BCBAs in preschool or early-elementary classrooms who pick AAC tools.
✗ Skip if Clinicians serving only fluent speakers or adults.

01Research in Context

01

What this study did

The team pooled 24 past studies on AAC for kids with autism. They asked: Does the child’s age or IQ change how well PECS cards or speech tablets work?

They compared three tools: PECS, speech-generating devices (SGDs), and other picture sets. In total, the children were in the mix.

02

What they found

Both PECS and SGDs gave small-to-medium speech gains. The winner depended on the child.

Kids with autism only did best with SGDs. Kids with autism plus IDD did best with PECS. Preschoolers of any group made the biggest jumps.

03

How this fits with other research

Fleury et al. (2018) ran a head-to-head RCT in elementary schools and saw equal gains after four months. That seems to clash with the meta-analysis, but the RCT lumped all kids together and used a free tablet app with short training. The meta shows the match matters when you split by IQ and give longer teaching.

Gilroy et al. (2023) later tested only autistic kids with IDD and found PECS and high-tech AAC beat eclectic teaching. Their function-based setup extends the meta finding that PECS is the top pick for this subgroup.

Alfuraih et al. (2024) pushed PECS even further, showing three nonverbal children with severe ID (no autism) still learned to ask for items. This widens the meta result beyond the autism label.

04

Why it matters

Stop using the same AAC for every child. Run a quick IQ and age check. If the child has autism without IDD, grab an SGD and start mand training. If the child has both autism and IDD, open the PECS book at phase 1. Aim to begin before age 6; the payoff is largest then.

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Pull your client list, flag any preschoolers with autism-plus-ID, and move them to PECS phase 1 this week.

02At a glance

Intervention
augmentative alternative communication
Design
meta analysis
Population
autism spectrum disorder
Finding
positive
Magnitude
medium

03Original abstract

Individuals with autism spectrum disorders (ASD) and complex communication needs often rely on augmentative and alternative communication (AAC) as a means of functional communication. This meta-analysis investigated how individual characteristics moderate effectiveness of three types of aided AAC: the Picture Exchange Communication System (PECS), speech-generating devices (SGDs), and other picture-based AAC. Effectiveness was measured via the Improvement Rate Difference. Results indicated that AAC has small to moderate effects on speech outcomes, and that SGDs appear to be most effective when considering any outcome measure with individuals with ASD without comorbid intellectual/developmental disorders (IDD). PECS appears to be most effective when considering any outcome measure with individuals with ASD and IDD. SGDs and PECS were the most effective type of AAC for preschoolers, when aggregating across outcome measures. No difference was found between systems for elementary-aged and older individuals.

American journal on intellectual and developmental disabilities, 2014 · doi:10.1352/1944-7558-119.6.516