Background: Advances in international studies on self-determination point out the need for continuous efforts to deepen its understanding and implications. The aim of this study is to obtain a comprehensive pool of items to operationalize the self-determination construct that serves as a starting point towards a valid instrument based on the reports of others.
Method: We conducted a Delphi study of three rounds involving three panels of experts: ten professionals, five people with intellectual disability and six relatives of people with intellectual disability. Data analysis required both qualitative and quantitative methods.
Results: The initial pool of 131 items was refined through the different rounds to a final set composed of 115-some were removed and new ones were added. Content-based evidence is provided. In this study, the present authors generated a potential valid pool of items to develop a new measurement tool based on the latest advances on the self-determination theoretical framework.
Conclusions: The implications for future research focus on strengthening the knowledge of self-determination.
Keywords: Delphi study; assessment; consensus; content validity; experts; self-determination.
© 2018 John Wiley & Sons Ltd.