Which statement accurately describes the relationship between reliability and validity?

Which statement accurately describes the relationship between reliability and validity?

• A. Reliability is required for validity; you can be reliable but still not valid.
• B. Validity is required for reliability; you can be valid but still not reliable.
• C. Reliability and validity are unrelated concepts.
• D. A measure cannot be both reliable and invalid.

Answer: (A)

Reliability and validity are about how good a measurement is. Reliability means the results are consistent across repeated tests or items. Validity means the measurement actually measures what it’s supposed to measure. For a measure to be valid, it must be reliable—if results aren’t consistent, they can’t accurately reflect the intended construct. But reliability alone doesn’t guarantee validity; a test can give consistent results that are still off-target and not truly measuring the intended thing. For example, a scale that always adds 5 pounds is reliable (it’s consistent) but not valid for measuring true weight. Conversely, a measurement cannot be valid without being reliable, and a measure can be reliable yet invalid. That makes the statement that reliability is required for validity the correct one.

Reliability and validity are about how good a measurement is. Reliability means the results are consistent across repeated tests or items. Validity means the measurement actually measures what it’s supposed to measure. For a measure to be valid, it must be reliable—if results aren’t consistent, they can’t accurately reflect the intended construct. But reliability alone doesn’t guarantee validity; a test can give consistent results that are still off-target and not truly measuring the intended thing. For example, a scale that always adds 5 pounds is reliable (it’s consistent) but not valid for measuring true weight. Conversely, a measurement cannot be valid without being reliable, and a measure can be reliable yet invalid. That makes the statement that reliability is required for validity the correct one.