Here - Tilburg University

Author and presenter
Kruyen, Peter M.; Tilburg School of Social and Behavioral Sciences
Title
Test length and decision making: When is short too short?
Abstract
To efficiently assess multiple psychological attributes and to minimize the
burden on patients, psychologists increasingly use shortened versions of existing
tests. Meanwhile, the importance of psychological testing has increased. For
example, patients are routinely measured to monitor their progress in the course
of a therapy and to evaluate treatment programs. These measurements are not
only used to evaluate changes in the individual patient, but they are also used
by insurance companies to make financial decisions on whether or not to
reimburse certain treatment programs. However, the shortened tests are less
reliable compared to long tests and may therefore substantially impair reliable
decision-making.
In this study, we reviewed recent trends in the use of short tests and
examined the impact of test length reduction on individual decision-making.
First, we present the results of a literature review on the use and validation of
abbreviated tests in psychology. Second, we present the results of simulation
studies comparing the risks of making incorrect decisions for the long and
abbreviated tests. These simulations showed that the number of items needed to
take decisions about patients depends on various factors including the
application envisaged. For some applications five to ten items are sufficient,
whereas in other applications one needs at least twenty items.