The Effects of PECS Teaching to Phase III on the Communicative Interactions between Children with Autism and their Teachers (summary)



The majority of young children with autism spectrum disorder (ASD) have limited or no spoken language when they start school at around the age of 5. It has been suggested that up to two-thirds never acquire useful spoken language.

Teaching speech to this group can be a very lengthy process and throughout this children do not have an effective means of communication.

In addition children with a diagnosis of ASD often find it difficult to initiate communication, either spoken or using augmentative and alternative communication (AAC) systems, and need support to develop the ability to use spontaneous communication. This can be made worse by the fact that early attempts at communication are often difficult to understand and are therefore not effective. It has been identified as very important that children with ASD are provided with a clear and easy to use system of communication to enable them to develop their skills.

Many children who have ASD are less motivated than typically developing children by the social effects of communication such as praise and interaction, they are more rewarded by concrete effects such as getting an item they want.

Some teaching procedures used with children with ASD focus on the use of spoken communication and therefore require the child to have at least some spoken words. The Picture Exchange Communication System (PECS) was developed for use with children with ASD to enable them to develop communication without first having to have speech. The system is built around a child ‘exchanging’ a picture or symbol of a highly motivating item for the actual, desired object or event in a way that is integrated in to daily activities.

PECS has a specific structure of 6 phases, from exchange of a single picture for an item – initiating a request- to commenting spontaneously and in response to a question.

In most studies looking at the effectiveness of PECS there are no control groups of children who are not offered interventions to compare with the group receiving intervention. This study aimed to address this issue.


What did they do?

This study considered whether developing children’s spontaneous communicative initiation through the early stages of PECS up to phase III, which involves picture/object discrimination using a range of pictures, has any effect on interactions between children with ASD and their teachers.

The study intervention group was made up of 24 children who had a diagnosis of ASD and attended special education settings or specialist ASD units. In addition 17 children who also met the ASD criteria and attended similar educational settings formed a control group.

The children were all aged between 3 and 7 and were not PECS users prior to the study.

Each child in the intervention group received 15 hours of PECS teaching from members of the research team and, once they had achieved phase II, from their teachers. The intervention took place in a variety of school activities over a period of around five weeks. Control group children had no change in their usual classroom provision.

Observational assessments took place 6 weeks and one week before the intervention and in the week following its completion for the intervention group, and on two occasions around 6 weeks apart for the control group.

The observational assessment was divided into 5 categories of communicative intervention:

  • Total number of child to adult initiations
  • Number of child to adult initiations with a response from the adult
  • Total number of adult initiations with opportunity for the child to respond
  • Number of adult initiations with opportunity for the child to respond and with a respond from the child
  • Number of adult initiations with no opportunity for the child to respond


What did they find?

No significant difference was found between the first and second observations in all categories of communicative interaction considered for both groups of children.

Between the second and third observations there were significant increases in the total child to adult initiations, child to adult initiations with an adult response, adult to child initiation with an opportunity for the child to respond plus a response from the child and a significant decrease in the total adult initiations with no opportunity for the child to respond. The increased initiations by children in the intervention group were almost all PECS based.

The children in the control group did not show similar positive changes between the two observation sessions, there was an observed increase in the number of communication initiations by an adult that gave an opportunity for the child to respond, but the rate of child response did not increase.



The authors believe that their study shows that PECS can be used to develop spontaneous communicative initiations in children with ASD within 15 hours of teaching. This included generalisation across a variety of objects, activities settings and people. They state that including generalisation of PECS use to classroom activities at phase II, as was the case in this study, was critical in securing positive results. Involving teachers who would then continue to provide consistent reinforcement might mean that changes would be maintained. They conclude that under optimum conditions the first half of the PECS program can be a very effective AAC tool for use with children with ASD and enable access to the curriculum.



The teaching of discrimination of pictures/symbols at PECS phase III was not fully completed during the intervention, so findings about errors in discrimination and teacher’s responses to these are not available.

The PECS trainers were extra staff in the classroom, so the intervention group had more adult support than the control group which might have influenced the outcome.

The fact that teachers were aware of the researchers carrying out observations meant that it is possible that they increased the amount of PECS related communications used and aimed for the best possible outcomes for PECS; this level of support might not be possible to maintain over the long-term in a classroom.

Things you may want to look into:

Effectiveness of the Picture Exchange Communication System as a Functional Communication Intervention for Individuals with Autism Spectrum Disorders: A Practice-Based Research Synthesis

The Picture Exchange Communication System (PECS) What Do the Data Say?

A Review of the Efficacy of the Picture Exchange Communication System Intervention

The effectiveness of Picture Exchange Communication System (PECS) training for teachers of children with autism: a pragmatic, group randomised controlled trial

A Communication-Based Intervention for Nonverbal Children With Autism: What Changes? Who Benefits?

The Picture Exchange Communication System

Predicting progress in Picture Exchange Communication System (PECS) use by children with autism

National Autism Resources



Added to site June 2016