Education Endowment Foundation: Wechsler Individual Achievement Test – Third UK Edition for Teachers

SubscalesⓘList of subscales (if applicable)

Early reading skills, reading comprehension, word reading, oral reading fluency, spelling.

Publisher

Pearson Clinical

Test source

https://www.pearsonclinical.co.uk/Education/Assessments/Achievement/wiat-iii-uk‑t/wiat-iii-uk-for-teachers-wiat-iii-uk‑t.aspx

Guidelines available?ⓘAdministration guidelines available to the review team

Yes

Norm-referenced scores

Yes

Age rangeⓘSpecific population and age range that publisher states the test is intended/​suitable for. 

4 – 25;11 years

Key Stage

Key Stage 1, Key Stage 2, Key Stage 3, Key Stage 4, Key Stage 5

UK standardisation sample

Yes

Publication date

2018

Re-norming date

N/​a

Additional information about what the test measures

Literacy (word reading, fluency, comprehension and spelling skills).

Are additional versions available?

WIAT-IIIUK‑T (reviewed here) is a revision of WIAT-IIUKT and a version of WIAT-IIIUK. Norms and items have been updated, and new subtests added. WIAT-IIIUK was standardised on a national UK sample of 744 children and young people. WIAT-III was standardised on a national US sample of 3000 children.

Can subtests be administered in isolation?

Yes — separate scores (including standardised) are provided on each subtest.

Administration Group Size

Individual

Administration duration

Dependent on many factors. Administration times for each subtest by age and ability is presented on p8 of the examiner’s manual. Typically aprroximately 25 – 40 minutes for the full accessment. Subtests should rarely take >10 minutes to administer, with the exception of the reading comprehension subtest which may take older participants longer.

Description of materials needed to administer test

Materials included in the test kit: examiner’s manual (once familiar with procedures, the manual states that the examiner will not need to use the manual during administration), simulus book, oral reading fluency booklet, word card, record form, audio files (on USB flashdrive). Other recommended materials: clipboard, stopwatch/​watch with second hand, audio recorder.

Any special testing conditions?

Well lit, quiet environment free from disruptions and interruptions. 4 – 8 year olds should not have alphabet displayed in the room.

Is any prior knowledge/training/profession accreditation required for administration?

Yes

Is administration scripted?

The Examiner’s Manual (p3 – 4) highlights that the level of qualification required depends on usage. For example, highlighting that additional qualifications will be required if the information is to be used to inform applications for Access Arrangements. Page 5 of the Examiner’s Manual highlights that a different level of qualification is required for administration and scoring of subtests (without interpretation) under the supervision of a chartered or research psychologist. Individuals who have relevant special needs qualification, and who have training in the use of individually administered assessment instruments, are qualified to administer and interpret the WIAT-IIIUK‑T. However, it is the responsiblity of the examiner to ensure that their specific qualification meets the criteria specified for the organisation to which they plan to submit their results. In all cases, examiners should have training in the fundamental principles of assessment procedures, including how to establish and maintain rapport, elicit optimum performance, follow standardised administration procedures, understand psychometric statistics, score and interpret tests, and maintain test security. The examiner should have experience in testing students whose ages, linguistic backgrounds, clinical, cultural, and educational histories are similar to those of the students tested with the WIAT-IIIUK‑T. Only individuals who have received professional training in educational or psychological assessment should interpret the results of the WIAT-IIIUK‑T. These user qualifications are consistent with the guidelines set forth in the Standards for Education and Psychological Testing (Standards; American Educational Research Association [AERA], American Psychological Association, & National Council on Measurement in Education, 1999), and the International Guidelines for Test Use: Version 2000 (International Test Commission [ITC], 2000). Specialist teachers who hold suitable qualifications and who require access to the full WIAT-IIIUK‑T battery can administer the subtests and score the responses under the supervision of a chartered or research psychologist. In these circumstances, the administration and interpretation of the tests must remain under the supervision of the psychologist concerned. Note: Only chartered and research psychologists may use the discrepency analysis with the … [WISC-VUK, WPPSI-IVUK, WAIS-IVUK]… or access [those tests]. (p5)

Rating Construct

Does it reflect the multidimensionality of the subject?

Generic literacy (with specific subtests)

Construct validity comments (and reference for source)

Good detail about face validity for use for diagnostic purposes. Adaptations needed for Anglicisation from WIAT-III described in detail to the examiner’s manual. Construct validity is supported by moderate-strong intercorrelations between subtest age-based standard scores (.37 – .99, see p189), as well as appropriate correlations with previous versions of the WIAT. 79 children aged 6;2 – 16;10 completed WIAT-IIIUK and WIAT-IIUK with a testing interval of 14 – 49 days. Correlations were high or moderate for similar subtests (word reading .81; spelling .83) and lower for dissimilar subtests (word reading and numerical operations .28). See p189 of examiner’s manual for further detail. Evidence of contrasted group validity would have further supported diagnostic use, however would not be possible from the standardisation sample due to the nature of exclusionary criteria and stratification in sampling.

Rating Reliability

Summarise available comparisons

The examiner’s manual indicates good reliability. Good-excellent internal consistency (coefficients .81 – .97; SEM 1.5 – 8.35) (presented by age group and overall for each subtest). 95% confidence intervals 3 – 16; 90% confidence intervals 2 – 13 (presented by age group and subtest). Test-retest reliability and inter-rater reliability are not reported for the UK standardisation. Note that other measures of reliability are available that were established on the WIAT-III US standardisation, which are likely to be somewhat transferable, but here we limit to discussion of the UK studies.

Sources

Wechsler, D. (2018). Wechsler Individual Achievement Test – Third UK Edition for Teachers (WIAT-IIIUK‑T): Examiner’s Manual. London, UK: Pearson Assessment.