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Wechsler Individual Achievement Test-4 (WIAT-4)
Availability
Please visit this website for more information about the instrument: Wechsler Individual Achievement Test-4
Classification
Supplemental: Mitochondrial Disease (Mito)
Short Description of Instrument
WIAT-4 measures the academic achievement of individuals aged 4 through 50, and prekindergarten through Grade 12. It consists of 20 subtests used to evaluate listening, speaking, reading, writing, and mathematics skills.
Comments/Special Instructions
Administered by paper-and-pencil and/or using Q-interactive on an iPad.
Scoring and Psychometric Properties
Scoring:
  • Age-based and grade-based norms available

  • Core composites - reading, written expression, mathematics, total achievement

  • May be scored by hand, using Q-global, using Q-interactive

  • Standard scores for composites and individual subtests

 

Psychometric Properties:

  • Normative data is based on a representative, nationwide standardization sample collected through fall and spring semesters

  • Internal consistency reliability is high for the composite and subtest scores, and scores are highly consistent over a period of several weeks

  • Average composite reliabilities are excellent (0.90) on most subtests. Highest reliability coefficients include Basic Reading, Decoding, and the Dyslexia Index

  • Test-retest stability coefficients range from good to excellent (high .80s to .90s) on many subtests

  • Interscorer agreement is in the high 0.90s for most subtests

  • Evidence of convergent and discriminant validity

  • Evidence of clinical utility and test-criterion validity
Rationale/Justification
Strengths:

  • Can choose to administer a single subtest or any combination of subtests to assess achievement in one or more domains
References
Key References:

Breaux KC. Wechsler individual achievement test (4th ed.). NCS Pearson; 2020.

 

Breaux KC. Wechsler individual achievement test (4th ed.). Administration manual. NCS Pearson; 2020.

 

Breaux KC. Wechsler individual achievement test (4th ed.). Technical and Interpretive Manual. NCS Pearson; 2020.

 

Additional References:

Beaujean AA, Parkin JR. Evaluation of the Wechsler Individual Achievement Test-Fourth Edition as a Measurement Instrument. J Intell. 2022 May 22;10(2):30.

 

Canivez GL. Incremental criterion validity of WAIS-IV factor index scores: relationships with WIAT-II and WIAT-III subtest and composite scores. Psychol Assess. 2013 Jun;25(2):484-95.

 

Document last updated March 2024