FINAL COMMENT

•Improved the floor and ceiling of several subtests.

•Expanded the number and type of subtests to measure all eight areas of achievement specified by IDEA 2004 legislation.

•New or newly separate subtests include Early Reading Skills, Alphabet Writing Fluency, Sentence Composition, Essay Composition, Oral Reading Fluency, and three Math Fluency subtests.

•Limited ceiling for some subtests for the oldest students in the Above Average range. Although most subtests have a ceiling that is at least 2 SD above the mean, the ceilings for Sentence Building, Word Reasoning, Expressive Vocabulary, Oral Reading Accuracy, and Math Fluency (Addition, Subtraction, Multiplication) range from 117 to 128. At the highest age range, 15 of the 26 possible subtests have ceilings ≤144.

•The Spelling subtest no longer includes an excessive number of potential homonym confusions.

•Oral Discourse Comprehension is presented from a CD recording rather than being read aloud by the examiner.

•Extensive tryout data using samples with approximately proportional representation by sex and ethnicity.

•Easel format for presenting many subtest items.

•Error analysis procedures were expanded.

•Established links with the most recent Wechsler scales (i.e., WPPSI-III, WPPSI-IV, WISC-IV, WISC-V, WAIS-IV, 22222222111111111 WNV), and the DAS-II to enable clinicians to compare ability and achievement scores.

•Limited floor for some subtests for the youngest students with the lowest ability levels. For students age 6, raw scores of 0 correspond to standard scores in the “average range” (i.e., SS > 85) for Sentence Combining, Sentence Building, and Math Fluency (subtraction).

•The standardization sample is well stratified to match the U.S. population.

•Data were obtained from a stratified sample of 2,775 students in grades pre-K–12 (1,375 in the spring of 2008 and 1,400 students in the fall of 2008). From the overall grade sample, an overlapping stratified sample of 1,826 students ranging in age from 4 through 19 was also obtained.

•The standardization sample included students receiving special education services.

•We hope that examiners will take the time to read, study, and annotate their PDF copies of the Technical Manual.

•There are no college-age norms provided.

•The average reliability coefficients for the WIAT–III composite scores are all excellent (.91–.98).

•Average subtest reliability coefficients range from good (.83–.89) to excellent (.90–.97), with the exception of Alphabet Writing Fluency, which has an average reliability of .69.

22222222111111111

•Correlations between the WIAT-III Total Achievement score and overall cognitive ability scores range from .60 to .82 and are consistent with research-based expectations regarding typical correlations between ability and achievement measures. Such correlations provide evidence of divergent validity, suggesting that different constructs are being measured by the WIAT-III from those measured by each ability test.

•Strong face validity based on item content and skill development in reading, writing, and mathematics.

•Construct validity indicated by increasing scores across grades and ages.

•No alternative forms are available.

•Standard Errors of Measurement (SEm) are high for the Alphabet Writing Fluency (8.35 for Fall, Spring, and Age samples).

•The only academic achievement comparison was to the WIAT-II when the WIAT-III initially published (the KTEA-3 later provided correlations with the WIAT-III).