Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III).

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Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III).

Assesment Type

Patient Reported Outcome Measure (PROM) | Objective

Patient Group


Age Group

Infants (0-2 years)

ICF domain

Activity & Participation | Body Structure & Function | Environment & Personal

Area of assessment

Balance and co-ordination | Fine Motor | Gross Motor

Key description

All abilities, from 1 month – 42 months (3 years), including pre-term infants

Assesses developmental function over five domains: cognitive, language, motor, social-emotional, and adaptive skills.
Identifies strengths and weaknesses.
Two scales are conducted through parent questionnaires; social-emotional & adaptive behaviour.
The domains can be carried out together or used as stand-alone assessments.
Bayley-III is recognised internationally as one of the most comprehensive tools to assess children from as young as one month old
Growth scores can be used to chart intervention progress, and it's useful in programme evaluation, ongoing monitoring of progress and outcome measurement



Full kit £1,362.00 £1,521.64 inc VAT

Equipment required

Full Kit

Training required

2 day Training required to administer

Considerations & references

Valid and reliable measure of a child's abilities. Validity: 0.59-0.98
Validated for use in the UK using a wide range of children with varying abilities/disabilities.
Ideal for team-testing / multi-disciplinary teams where a professional in each area may assess the child.
Flexible - can administer one or more domain subtests individually
2 day training required and practice before competent in delivering assessments.


Time to complete
30-90 minu depending on age of child & experience of the examiner.
Test time reduces with experience
Upgraded from 2019 with additions of social-emotional, adaptive behaviour.






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