A personality test is a sample behavior acquired under standardized circumstances with
scoring rules to obtain information from the behavior sample. Special traits are measured
or outcomes predicted using a subject's behavior. To generate accurate information about
a subject's behavior, the test has to be administered under standardized conditions and
there should be a well defined approach to describe the subject's behavior in response to
the test. A good test must also be reliable and valid (Murphy & Davidshofer, 1998).
The purpose of testing is to evaluate behavior, mental abilities and other personal
characteristics to make judgments, predictions, and decisions about people (Aiken, 1997).
Tests are used for selections in business (job suitability), in schools (admission into
special classes), for placements and to indicate competency. Clinicians use tests to
determine a patient's hidden characteristics, pinpoint areas of pathology or adjustment
problems and to plan treatments. Tests can also be used to evaluate outcomes like
method effectiveness (Friedenberg, 1995).
A good test is designed cautiously and evaluated so that it produces accurate, useful
A reliable test measures scores consistently when they are reexamined with a same test
on another occasion or conditions (Anastasi & Urbina, 1997). Consistency in tests scores
is important as tests are used to make crucial decisions about people (Murphy &
Test-retest reliability involves administering a test to a group of individuals, re-
administering that same test to the same group some time later. The first and second sets
of scores are correlated to estimate the reliability (Murphy & Davidshofer, 1998). Errors
of measurement caused by differences in conditions when the two tests are administered
are taken into account (Aiken, 1997). Although simple, it presents difficulties. Practice
produces d...