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Evidence-Based Practices

PECS® is an Evidence-Based Practice (EBP) with over 190 published articles providing evidence of the effectiveness of the Picture Exchange Communication System® (PECS). See the full list of research articles here. The Pyramid Approach to Education®, a systematic framework for building effective learning settings, incorporates strategies that are evidence-based. See table below.

What does ‘evidence-based practice’ (EBP) mean? There are varying definitions of EBP among the fields of special education, speech language pathology, and behavior analysis. In Evidence-based Practices in Education (2012) authors Cook, Smith, and Tankersley define EBP as practices that are shown to be effective through high-quality research to meaningfully improve student outcomes.

The American Speech and Hearing Association (ASHA) defines EBP as the integration of clinical expertise/expert opinion, evidence gathered from the scientific literature and from client observation and data collection, as well as client/patient/caregiver perspectives. “When all three components of EBP are considered together, clinicians can make informed, evidence-based decisions and provide high-quality services reflecting the interests, values, needs, and choices of individuals with communication disorders” (ASHA).

In the peer-reviewed journal Behavior Analysis, Slocum et al. (2014) define EBP as a model of professional decision-making in which practitioners integrate the best available evidence with client values/context and clinical expertise in order to provide services for their clients.

The National Professional Development Center on Autism Spectrum Disorder (NPDC on ASD) identifies inclusion criteria for EBPs based on the necessity of having a sufficient number of empirical demonstrations of efficacy through high quality, peer-reviewed journal articles and replications of those demonstrations by independent research groups. To be identified as evidence-based, a category of practice must have at least:

  • 2 high quality group design studies conducted by 2 different research groups, or
  • 5 high quality single case design studies conducted by 3 different research groups and involving a total of 20 participants across studies, or
  • a combination of 1 high quality group design study and 3 high quality single case design studies conducted by two independent research groups.

Highlighted below are organisations and peer-reviewed articles that recognise PECS as an Evidence-Based Practice.

Organisations

Information Autism provides impartial, scientifically accurate and accessible information on autism and interventions designed to help autistic individuals.

  They give PECS a ranking of two ticks, out of a possible three, meaning that there is strong, positive evidence supporting the use of PECS. They say:

There is a very small amount of high-quality research evidence (five controlled trials) and a small amount of low-quality research (19 single-case design studies with three or more participants) into the use of PECS for autistic individuals. . . This research suggests that PECS may be an effective way to increase the social communication skills (particularly requesting) of some young autistic children who are non-verbal or who have limited functional speech. PECS is a straightforward and positive approach, cost effective and not overly time consuming to implement.  There is, however, much confusion regarding the correct use of PECS and it should only be implemented by appropriately trained individuals.

Peer-Reviewed Articles

Pyramid Approach to Education

The Pyramid Approach to Education, a systematic framework for building effective learning settings, it incorporates strategies that have been recognised by National Clearinghouse on Autism Evidence and Practice (NCAEP) as evidence-based practices.