Placentation Research - Meng Hu's Blog

CHAPTER 4
FIGURE 4.2 Example of Wechsler’s Matrix Reasoning subtest.
Simulated items similar to those in the Wechsler Intelligence Scales for Adults and
Children, San Antonio, TX. Copyright © 2005 by Harcourt Assessment, Inc. Reproduced
with permission.
be answered correctly to be considered average? superior? extremely
low? What about the number of nonverbal reasoning
problems? Will solving 25 of the 35 correctly yield a high score?
There is no way to answer these questions without first obtaining
a representative standardization sample and determining how
many items were solved correctly by the average child or adolescent
at each age in the sample. Looking at the norms for the
WISC-IV (Wechsler, 2003, Table A.1), we learn that the average
7 ½-year-old answered 12 of the 33 Information items correctly
and solved 13 to 14 of the 35 Matrix Reasoning items. For age
10 ½, those average values are 17 and 20–21, respectively, and at
age 15 ½, the averages are 22 to 23 Information items and 25 to
26 Matrix Reasoning items.
Now we know what average performance means on those
two subtests. Remember that 10 is the average scaled score on
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