Test validity

For verification and validation in science and engineering most generally, see Verification and validation.

Test validity is the extent to which a test (such as a chemical, physical, or scholastic test) accurately measures what it is supposed to measure. In the fields of psychological testing and educational testing, "validity refers to the degree to which evidence and theory support the interpretations of test scores entailed by proposed uses of tests".[1] Although classical models divided the concept into various "validities" (such as content validity, criterion validity, and construct validity),[2] the currently dominant view is that validity is a single unitary construct.[3]

Validity is generally considered the most important issue in psychological and educational testing[4] because it concerns the meaning placed on test results.[3] Though many textbooks present validity as a static construct,[5] various models of validity have evolved since the first published recommendations for constructing psychological and education tests.[6] These models can be categorized into two primary groups: classical models, which include several types of validity, and modern models, which present validity as a single construct. The modern models reorganize classical "validities" into either "aspects" of validity[3] or "types" of validity-supporting evidence[1]

Test validity is often confused with reliability, which refers to the consistency of a measure. Adequate reliability is a prerequisite of validity, but a high reliability does not in any way guarantee that a measure is valid.

  1. ^ a b American Educational Research Association, American Psychological Association, & National Council on Measurement in Education. (1999) Standards for educational and psychological testing. Washington, DC: American Educational Research Association.
  2. ^ Guion, R. M. (1980). On trinitarian doctrines of validity. Professional Psychology, 11, 385-398.
  3. ^ a b c Messick, S. (1995). Validity of psychological assessment: Validation of inferences from persons’ responses and performances as scientific inquiry into score meaning. American Psychologist, 50, 741-749.
  4. ^ Popham, W. J. (2008). All About Assessment / A Misunderstood Grail. Educational Leadership, 66(1), 82-83.
  5. ^ Nitko, J.J., Brookhart, S. M. (2004). Educational assessment of students. Upper Saddle River, NJ: Merrill-Prentice Hall.
  6. ^ American Psychological Association, American Educational Research Association, & National Council on Measurement in Education. (1954). Technical recommendations for psychological tests and diagnostic techniques. Washington, DC: The Association.