Aims: The aims of this thesis were twofold. First, to review the literature on parental locus of control and its role in psychological outcomes for parents who have a child with an intellectual disability (ID). Second, a research study aimed to explore levels of parental subjective wellbeing in a specific group of these parents: those who have a child with profound and multiple intellectual disabilities (PMID). More specifically, whether two different types of parental cognition, parental locus of control and recognition of positive gains of having a child with PMID, were predictive of parental subjective wellbeing. Method: A systematic review of the literature was conducted to address the first aim. For the research study, a single sample of parents and family caregivers (n=101) completed three quantitative self-report questionnaires as part of a within-participant, cross-sectional survey design. These included the Positive Gain Scale, a modified version of the Parental Locus of Control Scale, and the Warwick-Edinburgh Mental Wellbeing Scale . Results: The systematic review highlighted the influence of parental locus of control and other parental cognitions on parent and family psychological outcomes. The research study revealed that parental subjective wellbeing in this group of parents (N= 101) was lower than in the general population. Multiple regression analysis revealed that parental locus of control significantly predicted parental subjective wellbeing (β= -.279, t(2,99)= 9.419, p= .005), accounting for around 8% of the variance in WEMWBS scores, R2= .081, F(2,99)= 5.474, p= .006. Conclusions and implications: Although the systematic review and the research study highlighted the importance of parental locus of control for parents of children with ID, the results of the study suggest that other factors are also involved in influencing subjective wellbeing of parents of children with PMID. They also indicate a potential role for psychological intervention for parents and families with a focus on adjusting beliefs and expectations and promoting an internal parental locus of control. However, further research exploring the emotions and experiences of this group of parents is needed.

INTRODUCTION. Assessing the participation experiences of young people with significant intellectual and developmental disabilities (SIDD) in recreational activities is imperative to ensure these activities provide youth with optimal opportunities to develop skills needed for adulthood. Currently, no instrument accessible to youth with SIDD is available to asses these experiences. The Participatory Experience Survey (PES) and the Setting Affordances Survey (SAS) were developed to meet this need. METHOD. The PES was developed with input from a panel of youth with SIDD while they were participating in a summer program. A draft was then presented to three groups of stakeholders: parents of youth with SIDD, service providers, and experts in intellectual disability and/or program planning. After making revisions based on stakeholder feedback, cognitive interviewing was conducted with eight youth ages 14 – 22 with SIDD. Next, to examine feasibility of the PES, the survey was given to 10 youth with SIDD. After finalizing a draft of the PES based on youth feedback, questions for the SAS were written to align with topics on the PES. Finally, a program evaluation was conducted that provided an additional feasibility evaluation of the PES and SAS. RESULTS. Of the 24 initial questions on the PES, stakeholder groups identified 15 questions needing revision and suggested 7 additional questions. Youth feedback during cognitive interviewing identified 13 questions needing revisions and 4 needing removal. Changes were made to address three issues: word choice, understanding of concept, and questions relating to others. Administering the PES directly following an activity was found to be feasible, however, the length was shortened from 31 to 15 questions to provide an appropriate administration time (<5 minutes). CONCLUSION. The PES and the SAS proved to be relevant, accessible and feasible ways to assess the individual experiences of youth with SIDD in recreational settings and the affordances, measured objectively, of those settings. Use of these two measures may help programs to include young people with SIDD during program evaluations, resulting in better-structured, more supportive programs.