Reliability vs Validity: What does validity measure?

Reliability vs Validity: What does validity measure?

• A. Accuracy
• B. Consistency
• C. The similarity of results across raters
• D. The correlation between test halves

Answer: (A)

Validity is about how well a test measures what it is supposed to measure and whether the score interpretations are appropriate for the intended use. In other words, it captures the accuracy of the inferences we draw from the scores about the construct of interest. For example, if a test is intended to assess math reasoning, validity concerns whether the test truly reflects math reasoning and whether the resulting scores meaningfully relate to relevant outcomes, like performance in math-related tasks or courses. Reliability concepts—such as consistency of scores across time, across raters, or the internal consistency of test items—address precision and repeatability, not whether the test measures the right thing. A test can be reliable (consistent) but not valid if it yields consistent scores that do not accurately reflect the intended construct or support the intended interpretations.

Validity is about how well a test measures what it is supposed to measure and whether the score interpretations are appropriate for the intended use. In other words, it captures the accuracy of the inferences we draw from the scores about the construct of interest. For example, if a test is intended to assess math reasoning, validity concerns whether the test truly reflects math reasoning and whether the resulting scores meaningfully relate to relevant outcomes, like performance in math-related tasks or courses.

Reliability concepts—such as consistency of scores across time, across raters, or the internal consistency of test items—address precision and repeatability, not whether the test measures the right thing. A test can be reliable (consistent) but not valid if it yields consistent scores that do not accurately reflect the intended construct or support the intended interpretations.