Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Doctor of Philosophy


Health and Rehabilitation Sciences


Dr. Janis Oram Cardy


One of the best predictors of long-term outcomes for autistic children is development of language and social communication skills. Therefore, it’s not surprising that speech and language therapy is one of the most frequently accessed interventions for children with suspected or diagnosed autism. From a public health and family well-being perspective, identifying effective social communication interventions and better understanding the specific components that contribute to their effectiveness is critical. However, there is a lack of clarity about the most effective interventions. This dissertation addressed this important topic through three studies.

Study 1 examined the literature on interventions provided by speech-language pathologists (SLPs) to autistic preschool children through a scoping review. Findings indicated that current research captures the versatility of SLPs’ roles in supporting autistic children, and has markedly increased over the past decade. However, research with strong methodological rigor that captures the complex and individualized nature of interventions is needed, as are studies aligned with community practice.

Study 2 systematically reviewed and critically appraised research evaluating one type of intervention used by SLPs – developmental social pragmatic (DSP) interventions. Results revealed that DSP interventions positively impact autistic children’s social communication, but evidence for impact on children’s language was inconsistent.

Study 3 focused on better understanding one support built into DSP interventions and other programs – environmental modification – by exploring the relationship between children’s unstructured (symbolic and gross-motor) play environments and their social communication behaviours using linear mixed effect models. Results revealed that young autistic children were more likely to socially attend to caregivers in gross motor play and to focus their attention solely on objects during symbolic play. This study confirmed the importance of continued research focused on understanding the impact of unstructured play environments on children’s social attention and communication.

Together, this dissertation contributes to a broader understanding of SLP-delivered interventions for preschoolers with autism, begins the work of examining how specific ingredients included within in early interventions might interact with social communication behaviours, and provides suggestions for future lines of inquiry.

Summary for Lay Audience

This thesis aims to enhance our understanding of intervention programs offered by speech-language pathologists (SLPs) to children with autism. One of the best predictors of long-term outcomes for children with autism is development of language. Therefore, it is not surprising that speech-language pathology services are one of the most frequently sought-after services after children receive a diagnosis of autism. Three studies were conducted to better understand therapies offered by SLPs, their effectiveness, and specific ingredients within these interventions that might play an important role in supporting autistic children and their families. The first study involved searching all research published between 1980-2019 that investigated SLP-delivered therapies provided to preschool autistic children. This was done to identify how much research has been conducted, what types of therapies have been researched and to provide guidance for what kind of research needs to be done in the future. The second study evaluated the quality of the research on one particular type of therapy often use by SLPs when working with young children with autism. The third study investigated how symbolic and gross motor play environments impacted autistic children’s attention to their caregivers and their toys, how much they used language, and the complexity of the language they used. Together these studies contribute to a broader understanding of SLP-delivered therapies for preschoolers with autism and provide suggestions for future research.