About the Measure
| Domains | Omnibus |
| Subscales | Listening comprehension, oral expression, word reading, reading comprehension, spelling numerical operations and mathematical reasoning NB not all scales available for four year olds |
| Target Construct | Oral language: Listening comprehension Oral expression Literacy: single word reading, reading comprehension, reading speed and spelling. Numeracy: Numerical operations Mathematical reasoning |
| Description | Assesses single word reading, reading comprehension, reading speed, spelling and numeracy |
| Test Authors | Wechsler, D. |
| Publisher | Pearson (2006) |
| Psychometry | |
| Implementation |
Implementation details
| Respondent | Child |
| Prior knowledge Required | Psychologists , speech or occupational therapists, mental health professionals and health practitioners with appropriate Graduate and professional qualifications in their field of practice. |
| Scoring | Scoring clear and transparent, need to distinguish raw scale standard scores and norms. Writing scales challenging to evaluate |
| Time | 30 to 40 minutes |
| Age | 4 years to 25 years and 11 months |
Psychometric details
| UK norms | YES (from 6 years onwards only) |
| Norm / Criterion referenced | Norm referenced |
| Standardisation sample | 892 |
| Reliability | Reliability of age-based coefficients ranged 0.90 to 0.97. SEM of composites ranged 2.56 to 4.67. test retest ranged 0.88 to 0.95 |
| Criterion validity | Insufficient data in the public domain to evaluate |
| Construct validity | Data available for WIAT III ranging from .6 to .82, although this varies between scales |
| Concurrent validity | For reading and spelling WIAT correlated with SAT (0.72, 0.76), ITBS (0.78, 0.53) and CAT (0.84 , 0.74). Inter correlation between subtests was 0.33 and 0.86, and between composites 0.44 and 0.94. |