Wechsler Individual Achievement Test (WIAT-III )

The Wechsler Individual Achievement Test, Third Edition: Australian and New Zealand Standardised (WIAT-III A&NZ) is an individually administered academic achievement test. Its Australian and New Zealand norms cover ages 4 years to 19 years 11 months, from preschool to Year 12.

The WIAT-III examines learned skills in areas such as reading, writing, mathematics and oral language. It is not an intelligence test. A child psychologist may use selected WIAT-III subtests as part of a broader educational assessment to understand a child or young person’s academic strengths and difficulties.

What does the WIAT-III assess?

The WIAT-III includes 16 subtests. The psychologist selects the tasks that are relevant to the person’s age, school year and referral question, so not everyone completes every subtest.

• Oral language: listening comprehension and oral expression.
• Reading: early reading skills, word reading, decoding, reading comprehension and oral reading fluency.
• Written expression: spelling, sentence composition, alphabet writing fluency and essay composition where age appropriate.
• Mathematics: numerical operations and mathematical problem solving.
• Maths fluency: timed addition, subtraction and multiplication tasks where age appropriate.

What can WIAT-III results show?

Results can describe performance across the academic areas assessed and compare it with an appropriate age or school-year reference group. Patterns across subtests may help identify academic strengths, areas requiring support and questions that need further investigation. They may also contribute to educational planning when interpreted alongside the person’s learning history and other relevant information.

The WIAT-III does not diagnose a specific learning disorder by itself. A diagnosis requires broader clinical evaluation, including consideration of developmental and educational history, the quality of instruction, response to intervention, functional impact and other possible explanations. Test results also do not guarantee school adjustments, funding or placement in a particular program.

Is the WIAT-III an IQ test?

No. The WIAT-III measures academic achievement, while a cognitive assessment explores thinking and reasoning abilities. Depending on the referral question, a psychologist may recommend a cognitive assessment as well, but this is not automatically required for every educational assessment.

What happens during WIAT-III testing?

The WIAT-III is completed individually with a child psychologist. Activities vary according to age, school year and the subtests selected. The time required also varies, so the psychologist should confirm the planned scope after reviewing the referral question and relevant background information.

Results are most useful when interpreted with school information, previous teaching or intervention, observations and any factors that may have affected participation. If you are concerned about persistent difficulties with reading, spelling, writing or mathematics, book an initial consultation to discuss whether an educational assessment is appropriate.