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BENDER GESTALT and EMOTIONAL
PROBLEMS
John Willis answered a query about the use of the Bender
Gestalt's "Emotional Indicators." He noted at that time that
although there was a significant Chi-square statistic, he wondered about the
"odd way to discover" these behaviors. Below is John's response
and an extension of John's concern. Using Positive and Negative Predictive
Power statistics, more information about the Bender is revealed.
Elizabeth's Koppitz is sticking with her original assertion in the 1975 manual.
Emotional Good
Poor
Indicators Bender Bender
0 to 2 119
76
3 to 6
19 58
Chi-square was p < .01 at ages 8 to 10 and p < .001 at ages 5 to 7. "This
supports the hypothesis that children with poor visual-motor perception also tend to have a high incidence of emotional indicators on their Bender
records. Three out of four of all subjects with three or more emotional indicators were also found to have a poor Bender score. However, there were
subjects with good Bender scores who showed a high incidence of emotional indicators
while more than half of all children with poor Bender records revealed less [sic] than three emotional indicators. Thus it seems safe to
assume that the Developmental score and the emotional indicators on the Bender Test measure different aspects of a child's functioning but that both
are found more often together on the records of children with emotional problems than on those of children without emotional problems. A poor Bender
score alone, does not necessarily imply emotional problems, but if a child shows several emotional indicators as well as a poor Bender score, then
indications are that the child has serious emotional problems and that perceptual problems have probably contributed to his disturbance" (p. 142).
This still strikes me as an odd way to discover such behaviors as impulsivity, acting out, timidity, and shyness.
Using parameters about a test's diagnostic usefulness that
have been proposed by Elwood (1993), and using information taken from Elizabeth
Koppitz's The Bender Gestalt Test for Young Children, page 130, the
following is found:
Test specific parameters include
sensitivity, or the proportion of individuals with a disorder that exhibit the
sign (i.e., the proportion of children with Emotional Problems who receive
scores within the abnormal range -
in this case 43.4%) and specificity, or the proportion of individuals without a
disorder that do not exhibit the sign (i.e., the proportion of controls who
receive scores within the normal range -
in this case 86.8%).
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EP
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control
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>2
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59
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18
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77
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<3
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77
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118
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195
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136
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136
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272
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Sensitivity =
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43.4%
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Sensitivity =
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a/a+c
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Specificity =
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86.8%
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Specificity =
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d/b+d
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These two parameters are calculated in the research setting
by first knowing the diagnosis of the children (through test-independent
criteria) and noting how they perform on the test of interest. However, as
Ellwood (1993) points out, this is the opposite of the way an evaluator uses a
test. The evaluator starts with the test score and attempts to determine the
child's diagnosis. In order to judge the usefulness of a test for this purpose,
the evaluator will need to look at a test's sensitivity and specificity in light
of the disorder's base rate in their referral population.
For example, if a Bender was used as a screening measure on
a population of 1000 children in which 10% (100) of the children have
“Emotional Problems”, and that test gives an abnormal score for 43% of the
children with “Emotional Problems” (i.e., sensitivity) and gives a normal
score for 87% of the children without “Emotional Problems” (specificity),
the following diagnostic properties result.
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EP
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Control
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>2
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43
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32
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75
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<3
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57
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868
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925
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100
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900
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1000
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PPP =
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57.3%
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PPP =
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a/a+b
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NPP =
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93.8%
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NPP =
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d/d+c
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Using this table, one can calculate Positive Predictive
Power (PPP), or the chances that a child who receives an abnormal test score
actually has “Emotional Problems”. PPP = a/a+b = 43/75 = 0.57. A test with
43.4% sensitivity and 86.8% specificity has restricted usefulness as a
diagnostic tool if it is used on a population with a 10% base rate of the
disorder because if the child receives an abnormal score, (s)he is almost as
likely to be a control (42.6%) than a child with “Emotional Problems”
(57.3%)
Ellwood, R.W. (1993). Clinical discriminations and
neuropsychological tests: An appeal to Bayes' theorem. The Clinical
Neuropsychologist, 7, 224-233..
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