This study assessed the validity and usefulness of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) Low Motor/Vision accommodated version. Accommodations are adaptations to minimize impairment bias, without altering what the test measures. Of the items, 66% have Low Motor accommodations like enlarged materials; 62% have Low Vision accommodations.
Using a within-subject design, we tested 19 children with the accommodated and standard Bayley-III, in a randomly counterbalanced order. The children had motor and/or visual impairment and a chronological age between 22 and 90 months. The test administrators completed an evaluation form.
A subgroup of children benefited from the accommodations; 2 children obtained a large raw score difference. Test administrators considered the accommodations as practical, and advantageous for most children.
The Low Motor/Vision accommodated version seems to validly assess the development of this population. Future, larger-scale research should study whether the accommodations improve the construct validity of the Bayley-III.