Advances in the assessment of self-determination: internal structure of a scale for people with intellectual disabilities aged 11 to 40.
The AUTODDIS Scale gives a valid, fair way to measure self-determination across youths and adults with ID.
01Research in Context
What this study did
Granieri et al. (2020) checked if the AUTODDIS Scale truly measures self-determination in people with intellectual disability.
They gave the scale to youths and adults aged 11-40.
Then they ran math tests to see if the scale keeps the same meaning across age and gender groups.
What they found
The scale passed every test.
It shows factorial validity, so the questions hang together as one construct.
It also shows measurement invariance, so you can fairly compare scores from different ages and genders.
How this fits with other research
Moreira et al. (2025) later found the same pattern with the Portuguese Self-Determination Inventory.
Both studies prove the construct holds across disability status, age, and language.
Cheves et al. (2026) showed adults with ID can reliably self-report distress using the OWLS-ID.
Together these papers build confidence that people with ID can validly rate their own inner states, whether it is distress or self-determination.
Why it matters
You now have a solid ruler that works from age 11 to 40.
Use the AUTODDIS Scale at intake and every six months to track growth in choice-making, goal setting, and self-advocacy.
If scores stall, you can add self-determination goals to the ISP and show families clear numbers that prove progress.
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02At a glance
03Original abstract
BACKGROUND: Advances in theoretical frameworks of self-determination require the development of new assessment instruments. This study examines the dimensional structure of a self-determination scale and analyses the factorial invariance of its measurement across age and gender. METHOD: The AUTODDIS Scale was used to assess the self-determination of 541 people with intellectual disabilities aged from 11 to 40. RESULTS: Different models (correlational and hierarchical structures) of the scale were tested. The correlational model obtained from the exploratory structural equation model approach provided the best fit for the data. The results also supported measurement invariance across youths (aged 11 to 21 years) and adults (aged 21 to 40 years) and across genders. CONCLUSIONS: This study contributes to international research on self-determination and the development of assessment tools in this field, offering a better understanding of this multifaceted and complex construct. The results provide construct validity evidence regarding a new measurement tool tested across people aged 11 to 40, using information from third parties. However, further research is needed to explore the best ways to understand and assess the different factors related to self-determination.
Journal of intellectual disability research : JIDR, 2020 · doi:10.1111/jir.12762