Assessment & Research

Validity and suitability of the Bayley-III Low Motor/Vision version: a comparative study among young children with and without motor and/or visual impairments.

Visser et al. (2013) · Research in developmental disabilities 2013
★ The Verdict

Use the Bayley-III Low Motor/Vision version to get a fairer picture of cognitive skills in toddlers with mild to moderate motor or visual impairments.

✓ Read this if BCBAs who assess infants and toddlers with visual or motor delays in clinics or early-intervention teams.
✗ Skip if Practitioners working only with older or fully able-bodied clients.

01Research in Context

01

What this study did

Reus et al. (2013) tested a low-motor, low-vision version of the Bayley-III.

They gave the regular and the adapted test to toddlers with and without motor or visual impairments.

The goal was to see if the changes gave a fairer picture of thinking skills.

02

What they found

Kids with mild to moderate motor or vision problems scored higher on the adapted test.

Children without impairments scored the same on both versions.

The changes helped the impaired group without hurting the typical group.

03

How this fits with other research

Bartoli et al. (2019) adapted ToM Storybooks for blind children and also saw equal scores to peers when the tool fit the child.

Levin et al. (2014) looked at gross-motor scores and found totally blind kids far behind partially sighted peers. That study used the TGMD-II, a test that still needs full movement. The Bayley-III fix shows you can close the gap by removing motor demands.

Lanza et al. (2024) pooled 69 studies and showed vision loss lowers quality of life across childhood. Using the low-motor Bayley-III is one concrete way to catch cognitive strengths early, before participation drops.

04

Why it matters

If you test a toddler who can’t see well or move much, the regular Bayley-III may hide what they know. Switch to the Low Motor/Vision version and you get a truer baseline. That honest score guides better goals, saves hours of re-testing, and shows families what their child can do instead of what they can’t.

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→ Action — try this Monday

Flip to the Low Motor/Vision items in the Bayley-III manual next time you test a child who can’t reach or see the cards.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
104
Population
mixed clinical
Finding
positive
Magnitude
medium

03Original abstract

The aim of the present study was to examine the validity of the Bayley-III Low Motor/Vision version, and its suitability for children with motor and/or visual impairment(s). This version contains accommodated items, that is, adaptations to minimize impairment bias, without altering what the test measures. We hypothesized that the accommodations would not affect the item scores of children without impairment, and that children with impairment(s) would benefit from the accommodations. We tested 41 children without impairment and 63 children with impairment with both the standard Bayley-III and the Low Motor/Vision versions, in randomly counterbalanced order. The test administrators filled in an evaluation form. Results showed that the accommodations did not affect the test scores of children without impairment and did improve the test scores of children with impairment on the Cognition scale, while no improvement was found for the other scales. The test administrators indicated that the vast majority of the children with impairment had been able to show their abilities on the test and that the accommodations were beneficial in 29 out of these 52 cases. For some children, the accommodated instrument appeared to be unsuitable because the impairment was too severe. The conclusion is that the accommodations improve the validity of the Bayley-III when used with children with mild to moderate motor and/or visual impairment, especially with regard to the Cognition scale.

Research in developmental disabilities, 2013 · doi:10.1016/j.ridd.2013.07.027