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Psychological testing is a field characterized by the use of small samples of behavior in order to infer
larger generalizations about a given individual. The technical term for psychological testing is psychometrics. By samples of behavior, we mean observations of the individual over a limited amount of
time performing tasks which have usually been prescribed beforehand, often with a great deal of research into the responses of
members of a norm group. These
responses are often compiled into statistical tables that allow the evaluator to compare the behavior of the individual being
tested to the responses of the range of responses given by people in the norm group.
A useful psychological measure must be both valid (actually tests what is claims to test) and reliable (does it consistently).
Types of Psychological Evaluations
Norm-Referenced
IQ/Achievement Tests
IQ tests and academic achievement tests are the most familiar norm-referenced tests for most people. In
either of these types of tests, a series of tasks are presented to the person being evaluated, and the person's responses are
graded according to carefully prescribed guidelines. After the test is completed, the results can be compiled and compared to the
responses of a norm group usually composed of people at the same age or grade level as the person being evaluated.
IQ tests and academic achievement tests are designed to be administered to either an individual (by a trained evaluator) or to
a group of people (paper and pencil tests). The individually-administered tests tend to be more comprehensive, more reliable,
more valid and generally to have better psychometric characteristics than
group-administered tests. Of course, individually-administered tests are more expensive to administer because of the need for a
trained administrator (psychologist, school psychologist, or
psychometrician), and the
limitation of working with just one person.
Neuropsychological tests
Neuropsychological tests are specifically designed
tasks used to measure a psychological function known to be linked to a particular brain
structure or pathway.
They are typically used to assess impairment after an injury or illness known to affect neurocognitive functioning, or when used in research, to measure differences in certain neuropsychological
abilities between experimental groups.
Personality Tests
Psychological tests of personality function generally fall into the two broad categories of objective tests and projective
tests. Objective tests have a restricted response format, such as allowing for true or false answers. A prominent example of an
objective personality test would be the Minnesota Multiphasic Personality Inventory. Projective tests allow for a much
freer type of response. An example of this would be the Rorschach test,
in which a person states what they see in ink blots on ten cards.
There is considerable controversy regarding the value and validity of projective testing. Nevertheless, both types of tests
continue to be used in modern psychological practice.
Types of personality tests include the Rorschach test, the Minnesota Multiphasic
Personality Inventory, Myers-Briggs Type
Indicator, and the Thematic Apperception
Test. Critics have pointed to the Forer effect to suggest that some of
these appear to be more accurate and discriminating than the really are.
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