Advances in the assessment of self-determination: internal structure of a scale for people with intellectual disabilities aged 11 to 40.

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.

Assessing support needs in children with intellectual disability and motor impairments: measurement invariance and group differences.

BACKGROUND: This study assessed the equivalence of the measurement of support needs between children with intellectual disability (ID) and children with intellectual and motor disabilities (IMD) and compared both groups in the different domains of support. METHOD: The Supports Intensity Scale-Children's Version was used to assess the support needs of 713 children with ID and 286 children with IMD, mainly associated with cerebral palsy. RESULTS: The results supported measurement invariance between the group of ID and IMD, which allowed to conduct comparison between them. Children with IMD scored higher on support needs than did children without IMD, suggesting that children with IMD needed more support than their peers without motor impairments. Furthermore, the ID levels interacted with motor impairments: at the highest levels of ID, groups tended to be similar in support needs, with high scores and low variability. The greatest differences were found in the domains of Home and Community activities. CONCLUSIONS: This study points to the across-condition of the construct of support needs in populations with intellectual and developmental disabilities. However, additional mobility impairments should be considered during the evaluation and planning of systems of support. In this regard, the Supports Intensity Scale-Children's Version might have limitations when discriminating between samples with high support needs.