
Difference in Range between KBIT-2 and WIAT II Tests
By Inderbir Kaur Sandhu, Ph.D
Q:
My son is five and had a psych evaluation at his school. His
cognitive testing was significantly lower than his academic
assessment. I understand that the tests are measuring
different things. Why would there be such a difference in
ranges on the two tests?
standard scores:
KBIT-II
IQ Composite 101 53%ile
Verbal Scale 109 73%ile
Nonverbal Scale 92 30%ile
WIAT-II
Word Reading 128 97%ile
Numerical Operations 117 87%ile
Spelling 126 96%ile
A: I will provide a brief
overview of the two tests. Kaufman Brief Intelligence Test
-2nd Edition (KBIT–2) is used to measure both verbal and
non-verbal ability rather quickly and cost-effectively. The
nonverbal test is ideal for non-readers, the hearing
impaired, and learning disabled. As a quick guide to
intelligence, this test appears to correlate positively with
the Weschler's test. However, since this is a brief
estimator, a standardized comprehensive test may be required
for detailed results and analysis. The KBIT-2 yields three
scores: Verbal, Nonverbal, and the IQ Composite. The Verbal
score comprises two subtests (Verbal Knowledge and Riddles)
and measures verbal, school-related skills by assessing a
person's word knowledge, range of general information,
verbal concept formation, and reasoning ability. The
Nonverbal score (the Matrices subtest) measures the ability
to perceive relationships and complete visual analogies. All
Matrices items involve pictures or abstract designs rather
than words.
The Wechsler Individual Achievement Test -2nd Edition (WIAT
II) presents one item at a time without time limits, except
for the Written Expression subtest. It offers standard
scores, percentile ranks, stanines, and other scores, based
either on the student's age or grade, which is compared to a
nationwide sample of students.
The KBIT-2 is an intelligence test. Other intelligence test
are such as the Wechsler series, Woodcock-Johnson III (WJ
III) - Tests of Cognitive Abilities, the Stanford-Binet
Intelligence Scales etc. The WIAT II is an achievement test.
Other achievement tests are such as Nelson-Denny Reading
Test, Peabody Picture Vocabulary Test, Stanford Test of
Academic Skills, Wide Range Achievement Test, 3rd Edition (WRAT-III),
Woodcock-Johnson Psycho-Educational Battery, etc.
As you are aware of, both tests measure different areas of
human skills.
Intelligence tests attempt to measure one's intelligence
which is the basic ability to understand the world around
us, assimilate its functioning, and apply this knowledge to
enhance the quality of our life. It is predominantly a
measure of a potential (not a measure of what we may have
learnt in school, as in an achievement test). Because of
this, it is supposed to be culture-free.
Achievement tests, on the other hand are general assessments
given to individuals in order to measure their comprehension
of acquired skills and content. These tests attempt to
measure either how much one knows about a certain topic
(which is our achieved knowledge or how much of a capacity
we may have (which is our aptitude) to master material in a
particular area. These tests are used to place students in
appropriate level courses, and help students get additional
help if they need it
These tests may also be used to identify a learning
disability. If a student's score on the intelligence test is
at least two standard deviations (30 points) higher than
his/her scores on an achievement test, the student is
described as having a significant discrepancy between IQ and
achievement and, therefore, as having a learning disability.
You would need to see the overall scores to determine if
this is the case.
Both the test results should not be compared, rather should
be looked into in detail and analysed. Your son appears to
be able to grasp school learning well. The fact that he
scored lower on the intelligence test calls for some
attention. You may want to show the detailed results to the
school psychologist to find out if your concern is
legitimate. Best wishes to you.
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