Comparison of Test Scores
By Inderbir Kaur Sandhu, Ph.D
I'm writing regarding my son's test results at two different GT schools.
His is currently 5 yrs 1 month and will be enrolled in kindergarten in
the fall. His scores are as follows:
Kaufman Test of Educational Achievement: 2nd Edition
Kaufman Brief Intelligence Test 2nd Edition Verbal Reasoning percentile
rank: 87 Performance Reasoning percentile rank: 88 Composite Score
percentile rank: 92
Woodcock-Johnson Tests of Achievement, 3rd edition Age Equivalency: 5.9
Grade Equivalency: K.5
My questions are:
Are the test scores from the different schools consistent with one
another? One is reported as a percentile rank and one as a score so it
is difficult to tell.
How does this equate to IQ? Is there a way to determine IQ from these
Do these scores indicate 'giftedness'. My son qualified for both
programs, but I'm afraid that term is used loosely in this area. I don't
want to enroll him in a program that he is going to be overwhelmed in if
he doesn't truly belong there.
Any input you can provide would be greatly appreciated. Thank you for
Standardized tests give reliable scores regardless of where the tests
are taken due to high objectivity in marking. However, different tests
focus on different strength and should not be compared based on the
scores alone. It should be compared with the norms of the test, not with
another. All the intelligence and achievement tests taken are reliable
tests and the scores (with all conditions the same) should be reliable.
The percentile rank of a given value or score indicates the percent of
the population that scores below it. So, if it's a percentile rank of
92, that means 92% of the population scores below that (which can also
mean that he is in the top 8%). The other score is the standard score.
Most tests including The Kaufman Brief Intelligence Test (KBIT) provide
raw scores, scaled scores, and intelligent quotient (IQ) scores. Raw
scores are scores expressed in their original form without statistical
treatment (such as the number of correct answers on a test). These
scores are transformed to the standard scores. A standard score is a
derived score as opposed to a raw score. Standard scores are derived
scores because they are “derived” from the standard deviation and the
mean (average) of the variable in question. Standard scores are superior
in many ways to other derived scores such as percentile ranks.
As a rule of thumb, in most intelligence tests, giftedness is recognized
as IQ 130 or above, or more than two standard deviations above the norm.
There should be an IQ score for the KBIT and the WPPSI - not only the
scores indicated. Check with the school. Achievement tests do not
provide IQ scores.
The scores on the intelligence test appears on the high side, hence it
is possible that your son has met the cut-off point for a gifted
program. Furthermore, the admission in a gifted program is rather
stringent; hence I believe he must have scored very well to be selected
in such a program. The tests are a rather standardized measure to screen
children suitable for the program so there should not really be a reason
to worry too much; unless you have some concerns that the school may be
unaware of. In that case, you would need to speak to someone at the
school. For now, I think a gifted program is suited for him; the only
choice is between the two schools. Hope the explanation helped and best