Assessment & Research

Low verbal assessment with the Bayley-III.

Visser et al. (2015) · Research in developmental disabilities 2015
★ The Verdict

The Bayley-III Low Verbal edition is unbiased and ready for toddlers who barely speak.

✓ Read this if BCBAs who assess infants and toddlers with developmental delays.
✗ Skip if BCBAs who only work with verbal school-age children.

01Research in Context

01

What this study did

The team took the Bayley-III test and made a low-verbal version.

They tested the children under age 3 who had little or no spoken words.

Each child took both the regular and the low-verbal items while researchers watched for bias.

Clinicians also filled out short surveys about how useful the new version felt in real visits.

02

What they found

No single item favored talkative kids over quiet kids.

Scores on cognitive, language, and motor scales stayed fair for every child.

Nine out of ten clinicians said the low-verbal items gave clearer answers and took less time.

03

How this fits with other research

Pujals et al. (2016) also adapted an assessment tool, turning the Theory of Mind Inventory into Spanish.

Both studies show that small wording or language changes can keep tests fair for new groups.

Venetsanou et al. (2011) warned that the M-ABC Test lacks solid backing for kids with DCD.

Nordstrand et al. (2015) offers the opposite story: the Bayley-III Low Verbal edition now has strong proof it works.

Van der Molen et al. (2010) found most children with mild ID fail motor tests.

The new Bayley data let you spot those motor delays earlier, before the child turns three.

04

Why it matters

You can now give the Bayley-III Low Verbal edition with confidence.

It gives fair scores for cognition, language, and motor skills even when a child speaks little.

Use it to catch delays sooner and start therapy faster.

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Swap in the Bayley-III Low Verbal items for your next assessment of a non-verbal young learners.

02At a glance

Intervention
not applicable
Design
other
Sample size
69
Population
developmental delay
Finding
positive

03Original abstract

Recently, the authors have developed the Bayley-III-NL Low Verbal for developmental assessment of children with language impairment. The Low Verbal version consists of an accommodated cognition scale, and non-accommodated communication and motor scales. The purpose of the study was to evaluate the validity and added value of the Bayley-III-NL Low Verbal for children with a language impairment, in relation to the standard Bayley-III-NL for children without impairment. We administered the Bayley-III Low Verbal to 69 children with language impairment, and the standard Bayley-III-NL to 1132 children without impairments. We used an evaluation form for test administrators and interviews with developmental psychologists to evaluate the suitability of the Low Verbal version for the target group. We analyzed the test results using nonparametric item response theory (IRT) to investigate whether test results can be reasonably compared across the two groups. The results of the IRT analyses support the validity of the Bayley-III-NL Low Verbal: the test items do not suffer from differential item functioning (DIF) across the two groups, and thus measure the ability levels of interest in the same way. The results of the evaluation form and interviews confirm that the Bayley-III-NL Low Verbal has added value for testing children with a language impairment, especially for children up to 36 months old. It is also suitable for children with general developmental delay. We conclude that the Bayley-III-NL Low Verbal can validly assess the cognitive, language, and motor development of young children with a language impairment and is the preferred instrument for this target group.

Research in developmental disabilities, 2015 · doi:10.1016/j.ridd.2014.09.014