What does validity refer to in measurement tools?

• A. Consistency of measurements across testers
• B. Extent to which an instrument measures what it is supposed to measure
• C. The time required to perform the measurement
• D. The cost of the instrument

Answer: (B)

Validity is about whether a measurement tool truly assesses the concept it’s designed to measure. It looks at the accuracy of the inferences you draw from the scores and whether the results reflect the actual construct of interest, not something else. For example, a survey intended to gauge pain should yield results that correspond to actual pain intensity rather than mood or desire to please the tester. Remember that a tool can be reliable—producing consistent results—without being valid if those consistent results don’t measure the intended construct. Time to administer and cost are practical factors, but they don’t determine validity.