The PPSI’s Planning, Development, and Empirical Evaluation

Abstract

The evolution of the evidence-based PPSI intervention at the heart of this book involved six stages of planning, development, and empirical testing as detailed in this chapter. First, we executed an extensive literature review that identified extant knowledge and lacunas in contemporary understanding of how to improve peer engagement in young children with ASD. Second, we conducted an empirical survey of practitioners that aimed at pinpointing their current habits of treatment, training, and needs for helping preschoolers with ASD to develop more fruitful peer engagement capabilities. Third, based on the literature review and survey, we developed the initial design for the three PPSI curricula targeting interaction, play, and conversation. Fourth, we examined the ecological validity and effectiveness of each of the PPSI content areas, through a pilot study as well as through focus groups of early educators and speech therapists. The lessons learned via this formative evaluation stage were processed and then followed by the necessary adaptations and modifications to the PPSI protocol. Fifth, we conducted a robust RCT study that examined the efficacy of the final, full PPSI version in facilitating the social engagement of 65 preschoolers with ASD. Participants with ASD were randomly assigned by preschool to one of four study groups comprising three intervention groups (interaction, play, and conversation) and one control group who received delayed PPSI intervention. Trained on-site facilitators led the PPSI in 23 preschools. Results showed that all three intervention groups improved over time, each mainly in its own targeted peer-engagement domain, whereas the control group even deteriorated on some measures. Intervention groups also showed generalization to untrained domains (adaptive skills) and other settings (play complexity during preschool activities). Sixth, in the last stage of intervention evaluation, we examined the PPSI’s social validity and impact, including direct excerpts from PPSI facilitators. These diverse and detailed stages offer researchers and interventionists a deeper understanding of the model’s evolution. The empirical merit deriving from this systematic design, development, and testing process supports our recommendation that individualized needs-based holistic peer intervention, comprising all three domains, should be part of early ASD intervention.