Appletcollection Vertical Menu java applet, Copyright 2003 GD

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%).

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.

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..

Content on these pages is copyrighted  by Dumont/Willis © (2001) unless otherwise noted.