Meta-Analysis of PECS With Individuals With ASD: Investigation of Targeted Versus Non-Targeted Outcomes, Participant Characteristics, and Implementation Phase

Research in Developmental Disabilities

Ganz, J. B., Davis, J. L., et al. (2012).

Research in Developmental Disabilities, 33(2), 406-418.

This meta-analysis investigates the effects of the Picture Exchange Communication System (PECS) on targeted (functional communication) and non-targeted (challenging behavior, socialization, and speech communication) outcomes in preschool, elementary, and secondary age participants on the autism spectrum.

Not stated


Single-case experimental designs


For students on the autism spectrum, results demonstrated the strongest effects for the Picture Exchange Communication System (PECS) in the area of functional communication (IRD = 0.65, 95% CI = [0.59, 0.73]). Conversely, PECS in students on the autism spectrum accompanied by multiple disabilities demonstrated small to questionable effects for functional communication (IRD = 0.44, 95% CI = [0.25, 0.63]); however, differences were not significant in terms of comparisons across diagnostic categories. Findings were similar for non-targeted outcomes compared across diagnostic categories. Although results suggested modest or uncertain effects (IRD = 0.45, 95% CI = [0.35, 0.56]) for non-targeted outcomes (e.g., speech communication, challenging behavior), PECS did not appear to negatively impact behavioral, speech, or social outcomes. <br /><br />Results suggested that PECS may be more effective for younger children than for older students. For targeted outcomes, statistically significant differences were found between preschool age and elementary age students but not between preschool and secondary students or elementary and secondary students. These differences were not seen for non-targeted outcomes. Statistically significant differences for targeted outcomes variables were seen between studies that implemented the first three phases of PECS (IRD = 0.65, 95% CI = [0.57, 0.73]) and studies that implemented all six phases (IRD = 0.84, 95% CI = [0.72, 0.96]). Similar results were seen for non-targeted outcomes in terms of PECS phase completed.