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TEST SCORE LABELS - The
Hieroglyphics of Special Education
As one who "made the top half of the class
possible,"
I would add that "average" is determined
arbitrarily by the publishers or
authors of tests. For example, a
standard score of 110 is "average" on the WJ III and
most Pro-Ed tests, but High Average on the
Wechsler scales and Above Average on
the DAS.
The Manual for the VMI 4th ed. offers
several classification schemes, but
the one that appears to be official
calls "average" scores from 83 through 117!
A standard score of 83 is "Average" on the
VMI, "Low Average" on the Wechsler
scales and WJ III, and "Below Average"
on the DAS and most Pro-Ed tests.
Many speech and language tests define the
"average range" as 85 - 115, rather
than 90 through 109 or 110.
"Well, Mr. and Mrs. Parent, we were a
little concerned about Sally's Low
Average standard score of 85 on the
WISC-III Verbal IQ, so we administered the Verbal
scale of the DAS and, sure enough, Sally
scored 85, which is Below Average.
Her 85 on the DAS was lower than her
85 on the WISC. We thought it might be a
language problem, but the speech
pathologist reports that Sally's
scores of 85 were all Average after all
in spite of the discrepancy between the Low
Average WISC 85 and Below Average DAS
85."
Most tests use the term "scaled score" for
subtest standard scores with a mean of
10 and s.d. of 3, but Pro-Ed calls
them "standard scores" and usually uses
"quotient" for standard scores with a mean
of 100 and s.d. of 15.
"Also, Mr. and Mrs. Parent, Sally did much
better on Story Construction with a
standard score of 11 than she did on
the WISC Verbal Comprehension with a
standard score of 86."
Some evaluators carefully translate all
scores into a single scoring system
(such as one Cathy Fiorello offered on
this list some time ago; or the one
proposed in
Kevin McGrew, Dawn Flanagan, Sam Ortiz, et
al.'s Desk References and other books on
their integrated CHC Cross-Battery
Approach; or stanines). If we do make
such translations, we need to keep
reminding readers we have done so and need to append
explanations of the original classification
systems and our own system to the
report. If we stick with the original
scoring system for each test, we need to
explain the scoring systems very clearly.
What we must not do, IMHO, is believe our
own classification levels. If a score
of 79 suggests a possible problem, the
problem has not disappeared if the
score soars all the way to 80. A standard score of
85 is still at the 16th percentile no
matter what we call it. I have heard
evaluators report that they had really
thought the child had a problem, but everything
turned out to be OK because a score of 85
was "average" after all.
It is, I think, very good practice to use a
90% or 95% confidence band and report
all the classification labels
intersected by the band (e.g., "Below Average
to Average" or "Borderline to
Superior").
John
Willis
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