WIAT lll/ll By Christian, Reed, Mike and Madeline
Reliability and Validity
WIAT III is nationally standardized on 3,000 students and adults and features comprehensive normative information. The WIAT III has new and improved scoring rules that are featured in response to scoring studies, theoretical reviews by expert researchers, and usability reviews by teachers and clinicians Reliability coefficients for most of the WIAT–III subtests were obtained utilizing the split-half method. A subtest’s split-half reliability coefficient is the correlation between the total scores of items from each half of the subtest, corrected by the Spearman-Brown formula for the length of the full subtest. The average reliability coefficients for the WIAT–III composite scores are all excellent (.91–.98) and are generally higher than those of the individual subtests that make up the composite scores.Reliability is not reported for component scores of subtests. These scores are intended for qualitative use when interpreting subtest standard scores. These scores should not be used in isolation to make educational decisions; rather, they are intended to help develop a targeted plan for intervention.
Price
Composites and Subtests
How Long Does It Take? Pre-K: 35 minutes Kindergarten: 45 minutes Grades1-2: 80 minutes Grades3: 94 minutes Grades 4-12 (and older): 104 minutes Age 20-25: 95 minutes Age 26-35: 103 minutes Age 36-50: 97 minutes *All of these are the maximum allotted times, if a student gets 4 consecutive questions incorrect, they are not allowed to continue.
Written Expression ●Alphabet writing ●Spelling ●Sentence composition ●Essay composition
Oral Language ●Oral Language
Listening Comprehension ●Listening expression
Basic Reading Skills ●Early reading Skills ●Word reading ●Pseudoword decoding
Reading Comprehension ●Reading comprehension
Reading Fluency Skills ●Reading fluency Skills
Mathematics Calculations ●Numerical operations
Mathematics Reasoning ●Math problem solving ●Math fluency addition ●Math fluency subtraction ●Math fluency multiplication
Essay Composition
Scoring
Composite Score Profile Note. The vertical bars represent the confidence interval at 95% Copyright © 2009 NCS Pearson, Inc. All rights reserved. Produced in the United States of America.
Note. A negative difference indicates that the second composite has a higher score than the first composite listed in the comparison. Copyright © 2009 NCS Pearson, Inc. All rights reserved. Produced in the United States of America. Differences Between Composite Standard Scores ComparisonDifference Critical Value (Significance Level.01) Significant Difference Y/N Base Rate Oral Language vs. Total Reading12.12N>15% Oral Language vs. Basic Reading Y>15% Oral Language vs. Reading Comprehension and Fluency N>15% Oral Language vs. Written Expression N>15% Oral Language vs. Mathematics Y≤5% Total Reading vs. Basic Reading Y≤1% Total Reading vs. Reading Comprehension and Fluency Y≤5% Total Reading vs. Written Expression10.57N>15% Total Reading vs. Mathematics299.66Y≤5% Basic Reading vs. Reading Comprehension and Fluency Y≤5% Basic Reading vs. Written Expression Y>15% Basic Reading vs. Mathematics449.23Y≤1% Reading Comprehension and Fluency vs. Written Expression N>15% Reading Comprehension and Fluency vs. Mathematics Y>15% Written Expression vs. Mathematics Y≤5%
References Breaux, K. C. (2009). WIAT III technical manual. San Antonio, TX: Pearson. Lichtenberger, E. O., & Breaux, K. C. (2010). Essentials of WIAT III and KTEA II assessment. Hoboken, NJ: Wiley & Sons, Inc.