Psychology
in
the
Schoolc
Volume
31.
October
/9Y4
WISC-I11 CORRELATIONS WITH THE WIAT
JOHN
R.
SLATE
Arkansas
State
University
Correlations between WISC-Ill
IQs
and Index scores with the eight achievement
subscales
of
the WlAT were investigated for a sample
of
202
students with specific
learning disabilities,
115
students with mental retardation, and
159
students who failed
to qualify
for
special education services (total
N=
476).
Corrected correlations be-
tween the WISC-Ill Full Scale
IQ
and WlAT subtests indicated differences with the
correlations reported in the WIAT manual. Interestingly, our relationships were
generally higher than those previously reported. Only on one subtest, Basic Reading,
were significantly lower correlations than those reported in the WlAT nianual present.
Correlations between the Verbal Comprehension and Perceptual Organization Index
scores and WlAT subtests were almost all lower than those calculated between the
Verbal and Performance
IQs
and WIAT subtests; Implications are discussed, especially
those involving the use
of
correlations between ability and achievement measures in
regression formulas.
The Psychological Corporation recently published an achievement test, the Wechsler
Individual Achievement Test (WIAT,
1992),
to
be used in conjunction with the latest
edition
of
their child/adolescent intellectual measure, the Wechsler Intelligence Scale
for Children-111 (WISC-111; Wechsler,
1991).
The WIAT, consisting
of
eight subtests
that measure reading, math, writing, and expressive skills, is unique because it is the
only “achievement battery directly linked with the Wechsler scales”
(
WIA T
Manual,
1992;
p.
1).
This direct link, or co-norming
of
the Wechsler intelligence scales and achieve-
ment measure, can be beneficial in special education assessment because disability
categories such as Specific Learning Disability (SLD) and Mental Retardation (MR)
require that individual measures of intelligence and achievement be given (Individuals
with Disabilities Education Act [IDEA], the reauthorization
of
PL
94-142,
Education
for All Handicapped Children Act; USDHEW,
1977).
Because special education disability categories require the measurement
of
intelli-
gence and achievement, examiners need up-to-date information regarding the interrela-
tionships
of
intellectual and achievement measures. Due to the recency
of
the WIAT
(1992)
and the WISC-I11
(1991),
however, no published studies were found in which
the relationship between these measures for students with disabilities was investigated.
The WIAT manual
(1992),
though reporting the results
of
several studies on students
with disabilities, provides only mean scores of the WlAT and WISC-111 and, unfor-
tunately, does not report correlations
of
the WIAT subtests with the WISC-111. The
only correlations between the WISC-I11 and the WIAT that are reported are based on
the WIAT normative sample, of which only
7.4%
were children classified as SLD, MR,
speech/language impaired, seriously emotionally disturbed, or physically impaired. The
specific percentage of children labeled as either SLD
or
MR was not cited, nor were
correlations reported separately for each disability category.
Although inclusion
of
students with disabilities in the normative sample is com-
mendable, the extent to which WIAT and WISC-I11 relationships based primarily on
persons without disabilities generalize to persons with disabilities is unknown. It
is
with
Requests for reprints should be sent
to
John R. Slate, Department
of
Counselor Education, Arkansas
State University, State University,
AK
724674940,
278