Comparison of Ability-Achievement Discrepancies Among the Wechsler Individual Achievement

83 Pages·2017·3.4 MB·English

by  Tracy L. Cole

Eastern Illinois University
The Keep
Masters Theses Student Theses & Publications
1998
Comparison of Ability-Achievement Discrepancies
Among the Wechsler Individual Achievement Test,
Woodcock-Johnson-Revised Tests of Achievement,
and Wechsler Intelligence Scale for Children-Third
Edition in a Sample of Students Referred for
Evaluation of Learning Disabilities
Tracy L. Cole
Eastern Illinois University
This research is a product of the graduate program inSchool Psychologyat Eastern Illinois University.Find
out moreabout the program.
Recommended Citation
Cole, Tracy L., "Comparison of Ability-Achievement Discrepancies Among the Wechsler Individual Achievement Test, Woodcock-
Johnson-Revised Tests of Achievement, and Wechsler Intelligence Scale for Children-Third Edition in a Sample of Students Referred
for Evaluation of Learning Disabilities" (1998).Masters Theses. 1772.
https://thekeep.eiu.edu/theses/1772
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Comparison of Ability-Achievement Discrepancies Among the Wechsler
Individual Achievement Test, Woodcock-Johnson-Revised Tests of
Achievement, and Wechsler Intelligence Scale for Children-Third Edition in
(TITLE)
a Sample of Students Ref erred for Evaluation of Learning Disabilities
BY
Tracy L. Cole
THESIS
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF
Specialist in School Psychology
IN THE GRADUATE SCHOOL, EASTERN ILLINOIS UNIVERSITY
CHARLESTON. ILLINOIS
1998
YEAR
I HEREBY RECOMMEND THIS THESIS BE ACCEPTED AS FULFILLING
THIS PART OF THE GRADUATE DEGREE CITED ABOVE
13 "Ju\1 )'l'lg
DATE
July 24, 1998
DATE
1
Abstract
Under current IDEA definitions, a significant or severe discrepancy
between intellectual ability and academic achievement is the primary
criterion by which a student may be classified as having a specific learning
disability. By recommendation of the Work Group on Measurement Issues
in the Assessment of Learning Disabilities (1984), the most common method
of determining such a discrepancy is to calculate the discrepancy between an
individual's score on an individually administered intelligence test and
his/her score on an individually administered achievement test using a
regression-based formula to correct for the regression of IQ on achievement.
Because two previous studies suggested that the Wechsler Individual
Achievement Test (WIAT) produced lower scores in the areas of reading,
mathematics, and writing than the Woodcock-Johnson-Revised Tests of
Achievement (WJ-R ACH), the main focus of the current study was to
determine whether the two achievement tests identify significant
discrepancies consistently.
Data was collected anonymously from the files of 79 students who had
been administered the WIAT, WJ-R ACH, and Wechsler Intelligence Scale for
Children-Third Edition (WISC-III) as part of routine initial and reevaluations.
Correlations, differences in mean standard scores, and discrepancy agreement
statistics were calculated.
Discrepancies Between the WISC-III, WIAT, and WJ-R 2
Correlations among WIAT and WJ-R ACH subtests and composites
purporting to measure similar constructs yielded significant results.
However, consistent with previous research, WIAT scores were significantly
lower than WJ-R ACH scores in reading decoding, reading comprehension,
reading composite, math reasoning, and written expression. The WJ-R ACH
Dictation subtest produced significantly lower scores than the WIAT Spelling
subtest. Furthermore, the WIAT produced significantly more discrepancies
than the WJ-R ACH in the areas of Reading Comprehension, Written
Expression, and Writing Composite.
The clinical implications, limitations and future directions are
discussed.
Discrepancies Between the WISC-III, WIAT, and WJ-R 3
Acknowledgements
I would like to thank my committee members, Dr. Gary Canivez,
chairperson, Dr. Michael Havey, and Dr. Christine McCormick for their time
and suggestions. My sincere thanks to Dr. Carl Hall, Anne Lewallen, Cynthia
Hunt, and Sonja Castle for their professional concerns that necessitated this
research and for their generosity in providing the data for this study. Finally,
I would like to express my thanks to Brian and Samuel Cole for their
patience, love, and assistance throughout this journey.
Discrepancies Between the WISC-III, WIAT, and WJ-R 4
Table of Contents
Title Page i
Abstract 1
Acknowledgements 3
Table of Contents 4
List of Tables 5
Introduction 6
Method 16
Participants 16
Instruments 16
Procedure 21
Data Analysis 21
Results 24
Discussion 35
References 49
Appendix 53
Discrepancies Between the WISC-III, WIAT, and WJ-R 5
List of Tables
page
Table 1 Pearson Product-Moment Correlation Coefficients 25
Between the WIAT and WJ-R ACH
Table 2 Pearson Product- Moment Correlation Coefficients 27
Between the WISC-III and WIAT
Table 3 Pearson Product-Moment Correlation Coefficients 28
Between the WISC-III and WJ-R ACH
Table 4 WIAT and WJ-R ACH Descriptive Statistics 30
Table 5 Discrepancy Agreement Statistics of Significant 33
WISC-III-WIAT and WISC-III-WJ-R ACH Discrepancies
Using WIAT Discrepancy Norms
Table 6 Discrepancy Agreement Statistics of Significant 34
WISC-III-WIAT and WISC-III-WJ-R ACH Discrepancies
Using WIAT-WISC-III Exact Correlations
Table 7 Discrepancy Agreement Statistics of Significant 35
WISC-III-WIAT and WISC-III-WJ-R ACH Discrepancies
Using Default Correlation of .65
Discrepancies Between the WISC-III, WIAT, and WJ-R 6
Comparison of Ability-Achievement Discrepancies Among the Wechsler
Individual Achievement Test, Woodcock-Johnson-Revised Tests of
Achievement, and Wechsler Intelligence Scale for Children-Third Edition in
a Sample of Students Referred for Evaluation of Learning Disabilities.
According to the Individuals with Disabilities Education Act (IDEA;
United States Department of Education [USDE], 1992), an individual may be
classified as having a learning disability in any of the following seven areas:
oral expression, listening comprehension, written expression, basic reading
skill, reading comprehension, mathematics calculation, and mathematics
reasoning. One criterion for the diagnosis of a learning disability is a
significant discrepancy between intellectual ability and achievement (USDE,
1992, p. 44823). Since the passage of P.L. 94-142, the evaluation and diagnosis
of learning disabilities has stirred much debate over several problems
associated with the classification of the disability. Many of the problems stem
from ambiguities in the definition of learning disabilities, as presented in P.L.
94-142. In this definition, classification of a learning disability:
is made based on (1) whether a child does not achieve commensurate
with his or her age and ability when provided with appropriate
educational experiences, and (2) whether the child has a severe
discrepancy between achievement and intellectual ability in one or
Discrepancies Between the WISC-III, WIAT, and WJ-R 7
more of seven areas relating to communication skills and
mathematical abilities.
These concepts are to be interpreted on a case by case basis by the
qualified evaluation team members. The team must decide that the
discrepancy is not primarily the result of (1) visual, hearing, or motor
handicaps; (2) mental retardation; (3) emotional disturbance; or (4)
environmental, cultural, or economic disadvantage. (Federal Register,
1977, ~ p. 65082)
According to Reynolds (1984), a severe discrepancy between aptitude
and achievement represents the only characteristic of a learning disability that
is agreed upon in the field. However, the federal government did not
provide criteria for determining a severe discrepancy in the final rules and
regulations. Individual states were allowed to adopt and implement, within
the parameters of the federal definition, criteria for diagnosing learning
disabilities. Consequently, the models adopted from state to state for
determining the existence of a severe discrepancy are varied and, at times,
inadequate. In addition, the number of students diagnosed with a learning
disability tripled from 1976 to 1982. It was in this context that USDE-SEP staff
recommended that the Work Group on Measurement Issues in the
Assessment of Learning Disabilities be formed to recommend best practices in
determining severe discrepancies (Reynolds, 1984).