Technical terms in the WISC-IV
By Inderbir Kaur Sandhu, Ph.D
Q:
My 9 year old ADHD son scored 97.5% for Perceptual Reasoning
and 95.5 % Visual Perception, IQ 120. Although I went to
Harvard, all the web info is so jargon laden that I have no
real idea of what they are talking.
In layman's English, what are the general definitions that
are not so mushy that they are bereft of meaning to simple
folk ? I can not brag to my elite friends if I can't define
the terms myself.
A:
I have answered a number on queries regarding the score
interpretation of the WISC-IV (I assume that this is the
test version that your son took since it was not indicated),
so I suggest that readers go through previous newsletters
for more details on the test.
In this case, based on the FSIQ, your son should be in the
bright category (please read the answer on "
Stanford-Binet 5 Score Interpretation").
This test consists of 10 core subtests with five additional
subtests. All of these are summed up to four indexes which
makes the full scale IQ (FSIQ) which ranges from 40 (lowest)
to 160 (maximum score). The WISC-IV indexes are the:
-
Verbal Comprehension Index (VCI)
-
Perceptual Reasoning Index (PRI)
-
Working Memory Index (WMI), and
-
Processing Speed Index (PSI).
On individual scores, the following table may be helpful as
a guide of average scores of children in the gifted.
| Group |
VCI |
PRI |
WMI |
PSI |
FSIQ |
| Gifted Average |
124.7 |
120.4 |
112.5 |
110.6 |
123.5 |
On the jargons, I hope the following details would help in
understanding the test further. I will further explain some
of the concepts in the subsets that may be a little more
difficult to understand:
Verbal Comprehension Index (VCI)
A measure of verbal concept formation (core subtests include
similarities, vocabularies and comprehension). Here,
children are assessed based on their ability to listen to a
question, draw upon learned information from both formal and
informal education, reason through an answer, and express
their thoughts aloud. This is indeed a good predictor of
readiness for school and achievement orientation. Results
can be influenced by background, education, and cultural
opportunities.
Similarities: Designed to measure verbal reasoning and
concept formation. It also involves auditory comprehension,
memory, distinguishing non-essential and essential features,
and verbal expression.
Perceptual Reasoning Index (PRI)
A measure of non-verbal and fluid reasoning – an ability to
perform mental operations, such as the manipulation of
abstract symbols (core subsets include block design, picture
concept and matrix reasoning). Children are assessed based
on their ability to examine a problem, draw upon
visual-motor and visual-spatial skills, organize their
thoughts, create solutions, and test them. This test enables
tapping of preferential skills for visual information,
comfort with novel and unexpected situations, or a
preference to learn by doing.
Block design: Designed to measure the ability to analyze and
synthesize abstract visual stimuli and nonverbal concept
formation. It also involves visual perception and
organization, visual-motor coordination, spatial
visualization, learning, and the ability to separate figure
and ground in visual stimuli.
Picture Concept: Designed to measure abstract, categorical
reasoning ability. The child is presented with two or three
rows of pictures and chooses one picture from each row to
form a group with a common characteristic. Solutions to
easier items are generally attained by reasoning based on
concrete representations, and the solutions to
more difficult items are obtained by reasoning based on more
abstract representations.
Matrix reasoning: Measure of fluid intelligence and a
reliable estimate of general intellectual ability. Four
types of matrices include continuous and discrete pattern
completion, classification, analogical reasoning, and serial
reasoning.
Working Memory Index (WMI)
A measure of working memory (core subsets include digit span
and letter number sequencing). Children are assessed based
on their ability to memorize new information, hold it in
short-term memory, concentrate, and manipulate that
information to produce some result or reasoning processes.
Results can tap on a child's level of concentration,
planning ability, cognitive flexibility, and sequencing
skill.
Digit Span: Digit Span Forward requires the child to repeat
numbers in the same order as read aloud by the examiner,
whereas Digit Span Backward requires the child to repeat the
numbers in the reverse order of that presented by the
examiner. The shift from the Digit Span Forward task to the
Digit Span Backward task requires cognitive flexibility and
mental alertness.
Letter number sequencing: The child is presented a series of
numbers and letters. The child repeats numbers then letters
in proper order. This involves sequencing, mental
manipulation, attention, short-term auditory memory,
visuospatial imaging, and processing speed.
Processing Speed Index (PSI)
A measure of processing speed (core subsets include coding
and symbol search). Children are assessed based on their
ability to focus attention and quickly scan, discriminate
between, and sequentially order visual information.
Persistence and planning ability is required here and is
related to reading performance and development.
I hope the above has been helpful. Unfortunately, the above
concepts are specific to the test, hence it is difficult to
use simpler explanation terms as the meaning may be
compromised with. It is also advisable to speak to your
child's tester to see if s/he would be able to explain the
scores better verbally. Good luck!
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