Which statement best defines test validity?

• A. The degree to which the test is fair to all groups.
• B. The usefulness of the test in predicting future performance.
• C. The consistency of test results over time.
• D. The extent to which the test measures what it was designed to measure.

Answer: (D)

Test validity means the test measures what it was designed to measure. This focuses on whether the items and scoring actually tap the intended construct, and whether evidence supports that the resulting scores reflect that construct rather than something else. That’s why the statement claiming the test measures what it was designed to measure is the best definition of validity.

Regarding the other ideas: fairness is about bias and equitable treatment across groups, which relates to test usefulness but isn’t the definition of validity; predicting future performance describes a specific form of validity (predictive validity) but the general idea is broader; consistency over time describes reliability, not validity.