Standardized tests: Test validity

The internal validity of a test is the extent to which it measures what it is supposed to measure. The external validity of a test refers to how well it can be generalized to others in the population for which it was developed. There are 3 additional criteria or types of evidence for test validity: construct, content, and criterion validity.

Construct validity - refers to the association of the test with an underlying theory. Does the test produce a result that is in accord with an established theory? For example, according to psychoanalytic theory, anxiety is a common response to stressful events. A test that shows an increase in anxiety in people who have been traumatized would possess construct validity. More....

Content validity - sometimes known as "face validity." On the face of it, does the test or inventory look like it measures what it is supposed to measure? Does the content make sense? An item asking about how gears work would appear to measure mechanical ability. Asking someone to indicate on a checklist whether they are feeling happy or sad sounds like a good way to find about that person's mood.
Mechanical ability

Criterion validity - do the test results match up with other known measures of a characteristics (the criterion)? There are two (2) types of criterion validity: concurrent and predictive.

Concurrent validity - a test result is compared with another indicator (criterion) at the same time. For example, to check the concurrent validity of the State Anxiety Scale, it could be administered at the same time as the older, established Taylor Manifest Anxiety Scale. If both scales give the same result, then the newer one possesses criterion validity. It is valid because it gives the same result as a known criterion (standard). Predictive validity - the test result predicts a later outcome. Police selection example: Applicants who scored low on the test (but passed and were hired) had more discipinary citations in their records a year later than person who scored high on the test. The test has predictive validity in that it predicts (fortells) subsequent behavior.

Self-test #2

Next section: Projective tests