Differences in Self and Proxy Assessments of Self-Determination in Young People with Intellectual Disability: The Role of Personal and Contextual Variables

Background: Assessing self-determination in students with intellectual disabilities (IDs) is a primary step in facilitating progress monitoring. Researchers have developed both self and proxy assessments to favor a more in-depth evaluation of self-determination expression. However, to date, limited research has explored the congruence between both assessments. Methods: To address this need, the present study analyzes the differences between 219 adolescents with ID; 63% being males with an age range from 13 to 21 years (M = 16.8; SD = 1.72); and their teachers in their assessment of self-determination and explores which factors (students' age, sex, level of ID and opportunities at school) might explain those differences. The participants were recruited intentionally. Students with IDs completed two questionnaires: the AIR Self-Determination Scale and the Spanish version of the Self-Determination Inventory, which was also completed by their teachers. Results: Significant differences were found in the self-determination assessment, with teachers rating it lower. Further, students' sex and the opportunities they were provided at school to engage in self-determined actions were found to explain the differences in self-determination assessment. Conclusions: Research and practice initiatives to assess self-determination in young people with IDs must consider that informants' points of view might be influenced by students' sex and by contextual opportunities to engage in self-determined actions. Implications for further research and practice are discussed.