Purpose: This thesis aims to explore if and how professionals’ participation in professional development enhances the quality of education for autistic students, including the perspectives of autistic students, their parents, and professionals in pre- and primary school. Furthermore, the thesis directs attention to how professional development may lead to the development of accommodations in the learning environment to support autistic students. Four studies have been conducted to fulfil the aim, which in combination answer the research questions addressed in this thesis. The four studies comprise one systematic review and three empirical studies. Study I, the systematic research review, explored adaptations and modification strategies. Study II investigated how a professional development intervention designed as a lesson study changed attitudes and practices amongst preschool professionals. Studies III–IV were developed from study II, and used professional development to explore changes in the preschool (study III) and primaryschool (study IV) practice. In these studies, multiple stakeholders were included; professionals (teachers, pre- and school management), autistic students, and their parents.

Theoretical frameworks: Pragmatism is used as the umbrella framework capturing the methodology and methods, in combination with Communities of Practice (CoP) and Landscapes of Practice (LoP), are used to explain and discuss the results of the thesis.

Design/Approach/Methods: A multilevel mixed methods research design was applied in this thesis. Following the concept of mixed methods, the integration was applied in three phases: research design, methods, interpretation and reporting. In the three empirical sub-studies, variants of mixed methods were alsoused in the designs. The results of the sub-studies are synthesized with a narrative synthesis.

Findings: The results from the synthesized sub-studies indicate that professional development contributes to changes in professionals’ attitudes, increased knowledge, and strategies to accommodate, the latter more vaguely. Professionals could identify more changes than parents and autistic students. Barriers to implementation were found, such as lack of resources and physical environment. Enabling factors were identified as participation (collaborative aspects). Discrepancies were detected across participants and contexts.

Conclusions: Based on the results of the included studies and the synthesized result, it is possible to conclude that professional development can contribute to changes, most prominent when exploring professionals’ views. The more distinct changes resided in changes and development in attitudes contributing to changes in mindset and increased knowledge. Furthermore, a lack of prerequisites, such as resources, may hinder the sustainability of professional development and, on a larger scale, inclusive education, which needs to be addressed further. To conclude equity for autistic students is a challenging issue for the Swedish school context, and is not yet fulfilled for this student group.

Originality/Value: This thesis offers insights into a complex area, includes multiple stakeholders and provides a comprehensive understanding of the phenomena. Including young autistic students as active participants could be considered to be of great value. The findings could be of interest to both the research community and school practice.