Examination of the role of training and fidelity of implementation in the use of assistive communications for children with autism spectrum disorder: a meta-analysis of the Picture Exchange Communication System

Autism spectrum disorder (ASD) affects about 1.4% of children in the US. People with ASD have difficulty with social cues, eye contact, communication and engagement with others. The authors reviewed literature from 2010-2018 to fill in the gaps left by previous meta-analyses and more specifically to examine the fidelity of implementation and the effectiveness of Picture Exchange Communication System (PECS) training. Two methods were used to examine and analyse the selected studies in this quantitative synthesis. Those two methods included analysis of moderators using a linear regression and analysis of effect size using Cohen's d. A search of terms yielded 496 articles initially. The total number of studies (k) selected for the analysis was 19. The weighted average effect size for randomised experimental design when corrected for sample size is d = 0.339 (Small), and for the single case study designs the effect is d = 0.815 (Large).