Examining measurement invariance and differences across groups in the support needs of children with and without intellectual disability.

Background The purposes of this study were to empirically determine whether the support needs construct is generalizable across children with and without intellectual disability and to conduct cross-group comparisons to explore how extraordinary and non-extraordinary support needs differ in children. Method One thousand thirty-six children (814 with intellectual disability 222 without intellectual disability) were assessed using the SIS-C. Results The SIS-C achieved scalar invariance between children with and without intellectual disability. Cross-group comparisons revealed differences in variances, in correlations between factors and significant latent mean differences for all factors. Conclusion Results show that the support needs construct is generalizable to children with and without intellectual disability and that there are no qualitative differences in how they show their support needs, so typically developing children can be used as a reference group to explore differences between extraordinary and non-extraordinary support needs. Conceptual and practical implications are discussed, and future lines of research are provided.