About the Measure
| Domains | Omnibus |
| Subscales | Cognitive, Language, motor development and adaptive behaviour |
| Target Construct | Oral language: Receptive and expressive language skills. Social emotional: Communication of needs and self-regulation. |
| Description | Designed to assess the cognitive, language and motor functioning of infants and young children to quickly determine whether a child is progressing according to normal expectations and to determine if future evaluation is needed. When in-depth assessment of cognition, language or motor functioning is needed, the full Bayley-III scales should be used. |
| Test Authors | Bayley, N. |
| Publisher | Pearson (2005) |
| Psychometry | |
| Implementation |
Implementation details
| Respondent | Child |
| Prior knowledge Required | Individually administered by speech or occupational therapists, mental health professionals and health practitioners with appropriate Graduate and professional qualifications in their field of practice. |
| Scoring | Complex sets of items a, Scoring requires care to establish norms |
| Time | 30 to 90 minutes |
| Age | 1 month to 42 months |
Psychometric details
| UK norms | YES |
| Norm / Criterion referenced | Norm referenced |
| Standardisation sample | 1700 (221 in UK and Ireland) |
| Reliability | Reliability coefficients ranged from 0.91 to 0.93. Across all ages, average stability coefficients were .80 or higher. )info from web) |
| Criterion validity | Comparison of children’s scores on the Bayley-III and the BSID-II, WPPSI-III, PLS-4, PDMS-2 and ABAS-II Parent/Primary Caregiver Form (ABAS-II-P), all no valid tests. Correlations were only moderate. |
| Construct validity | Test reviews report as insufficient. The Bayley-III cannot be considered a valid test for identifying language disorder/developmental delay and should not be used to identify children with language impairment. |
| Concurrent validity | The highest correlation between the Bayley–III and the WPPSI–III was between the Language composite and the VIQ (r = .83). There is very little difference between the Bayley–III Language composite mean and the WPPSI–III VIQ and FSIQ (98.9, 100.3, and 98.0, respectively). |