Statistics Definitions > Construct Validity
What is a Construct?
When you’re talking about a construct in relation to testing and construct validity, it has nothing to do with the way a test is designed or constructed. A construct is something that happens in the brain, like a skill, level of emotion, ability or proficiency. For example, proficiency in any language is a construct.
What is Construct Validity?
Construct validity is one way to test the validity of a test; it’s used in education, the social sciences, and psychology. It demonstrates that the test is actually measuring the construct it claims it’s measuring. For example, you might try to find out if an educational program increases emotional maturity in elementary school age children. Construct validity would measure if your research is actually measuring emotional maturity.
It isn’t that easy to measure construct validity–several measures are usually required to demonstrate it, including pilot studies and clinical trials. One of the reasons it’s so hard to measure is one of the very reasons it exists: in the social sciences, there’s a lot of subjectivity and most constructs have no real unit of measurement. Even those constructs that do have an acceptable measurement scale (like IQ) are open to debate.
Statistics and Construct Validity
After World War II, many efforts were made to apply statistics to construct validity, but the solutions were so complicated they couldn’t be used in real life. Experience and judgment of the researcher are the acceptable norms to testing construct validity. In some circumstances, such as in clinical trials, statistical tests like a Student’s t-test can be used to determine if there is a significant difference between pre- and post tests.
Brown, J. D. (1996). Testing in language programs. Upper Saddle River, NJ: Prentice Hall Regents, pp. 231-249.
Dimitrov, D. M., & Rumrill, Jr, P. D. (2003). Pretest-posttest designs and measurement of change. Work: A Journal of Prevention, Assessment and Rehabilitation 20(2), 159-165.