Does it work?
There are several well-designed research studies showing the usefulness of PECS (8). In one study of 18 preschool children with language delays, some of whom were diagnosed with autism, PECS generalized across communication partners and environments (6). These children were able to use PECS to communicate throughout their school days, not just during the training sessions. Further, almost half of these children stopped using PECS and started using natural speech within a year (6). One parent commented that "PECS turned on the light for communication" in her child (6). Similar results were found for two smaller, but still well-designed studies (5, 7).
A larger study of school-aged children found significantly increased use of PECS when adults trained in the use of PECS were in the classroom. The study involved 6 half-days of PECS intervention per month for 5 months. While use of PECS by the children increased, there was no significant increase in verbal language use (9). The children's use of PECS diminished after classroom visits by the trained adults were stopped (9).
Recently, a comparison was made between PECS and another popular AAC technique, Responsive Education and Prelinguistic Milieu Training (RPMT). The results showed that children with autism trained in PECS were more verbal than those for whom the RPMT approach was used (10).
Overall, the evidence supports the use of PECS as a tool for developing natural communication in children with autism, especially when it is taught before the child is six years old (3, 8).