316 ESSENTIALS OF KTEA™-3 AND WIAT®-III ASSESSMENT
Expert advisory and user panels were consulted during the development of the WIAT-III. Surveys of the experts and of try-out and standardization examiners were conducted at several points during the development process.
The availability of the computer scoring program packaged with the test serves to alleviate numerical errors often associated with complex tests. The scoring program also o ers several extremely useful features, including an enhanced skill analysis for core subtests as well as Intervention goal statements to assist with IEP development. Exclusive to the scoring program is the research-supported “pattern of strengths and weaknesses discrepancy analysis.”
The 52-page Enhanced Record Form for the WIAT-III provides ample space for recording responses, calculating scores by hand, profiling scores, calculating and assessing di erences between scores, and analyzing discrepancies between measures of cognitive abilities and WIAT-III scores by either the predicted achievement or, unfortunately, the simple di erence method. The front page of the Enhanced Record Form, where subtest scores are recorded and composite scores calculated and profiled, helpfully lists the page number on which each subtest begins.
The Pearson web page for the WIAT-III o ers valuable “Reference Materials,” including Assessing Writing Skills Using Correct-Incorrect Word Sequences (Breaux & Frey, 2009), a Quick Score Guide for WIAT-III Essay Composition, two Technical Reports (one of which needs to be updated), Patterns of Strengths & Weaknesses Models for Identifying SLD (Daniel, Breaux, & Frey,111111111 2010), and an explanation of WIAT-III Enhanced Content Modifications. We urge students and colleagues to make a habit of revisiting publishers’ web sites for all of the tests they use to check for updates. In the case of the WIAT-III, this e ort will be rewarded.
Normative Sample
Normative samples are important for tests, just as for opinion polls. If the normative sample does not resemble the population to whom examinees will be compared, scores will be misleading. The normative sample of the WIAT-III is described in Chapter 2 of the WIAT-III Technical Manual (Pearson, 2010a) and we consider it to meet or exceed good current practice and to provide a trustworthy basis for an individual’s scores.
Many examiners will be thrilled to have norms for adults. The WIAT-III provides norms for ages 20 through 25, 26 through 35, and 36 through 50 (Pearson, 2010a, Appendix L). Adult norms are rare in tests of academic achievement, and we welcome this addition.
Examinee candidates for the normative sample were extensively screened for potentially confounding issues that presumably might impair the validity of test performance. A complete list of the exclusionary criteria for the normative sample is presented in Table 2.1 (p. 15) of the Technical Manual. A representative proportion of students from various special clinical groups was also included in the normative samples to accurately represent the student population as a whole.
STRENGTHS AND WEAKNESSES OF THE KTEA™-3 AND WIAT®-III 317
Special group studies were conducted to examine clinical utility of the WIAT-III with intellectually gifted students and students with mild intellectual disability and disorders of reading, written expression, mathematics, and expressive language (Pearson, 2010a, pp. 49–59).
Reliability and Validity
The WIAT-III Composites, Indexes, and subtests generally have strong reliability. This topic is discussed at length in Chapter 3 of the Technical Manual. Test scores cannot be trusted unless the tests are internally consistent and likely to yield very similar scores for the same person under similar circumstances, so reliability is an essential foundation for any responsible use of test scores. It is a necessary, but not su cient, basis for application of test scores. A test can be reliable, but still not valid for a particular purpose, but without reliability, it cannot be valid for any purpose.
The average reliability coe cients for the WIAT–III composite scores are all excellent (.91–.98). Short-term (2 to 32 days) stability coe cients for the WIAT–III subtest and composite scores at all grades (Pearson, 2010a, pp. 37–38), range from
.73 (adequate) to .97 (reliable).
Validity data for the WIAT-III are discussed in Chapter 3 of this book, and in the WIAT-III Technical Manual (Pearson, 2010a, pp. 39–59). The subtest intercorrelations confirm expected relations between the111111111 subtests within composites and provide evidence of discriminant validity.
Validity evidence from comparisons with tests of tests of academic achievement and cognitive abilities supports the use of the WIAT-III for cognitive assessment and prediction of achievement. The relationships between the WIAT-III and the following cognitive measures were examined: WPPSI-III, WISC-IV, WAIS-IV, WNV, and DAS-II. It is very helpful for examiners to be able to predict WIAT-III achievement from both the DAS-II and Wechsler scales. The WISC-V Technical and Interpretive Manual (Wechsler, 2014b, pp. 101–105) provides WISC-V correlations with the WIAT-III. The WPPSI-IV Technical and Interpretive Manual (Wechsler, 2012b, pp. 104–108) provides WISC-V correlations with the WIAT-III. Unfortunately, the only academic achievement comparison was to the WIAT-II. However, the KTEA-3 Technical & Interpretive Manual (Kaufman & Kaufman with Breaux, 2014b) provides correlations, based on 73 examinees, between WIAT-III and KTEA-3 subtests and composites in Table 2.11 (pp. 64–65).
Administration and Scoring
The administration of the WIAT-III seems to flow a bit more e ciently than did that of the WIAT-II, and one reason for this may be the revised discontinue rules (for most subtests there is a consistent discontinuation rule of four consecutive failures), which have for the most part been shortened. Entry points and other essential information