Which statement best describes the relationship between reliability and validity?

Which statement best describes the relationship between reliability and validity?

• A. A test can be reliable but not valid
• B. Reliability and validity are the same concept
• C. A test cannot be reliable if it is not valid
• D. Validity guarantees perfect results

Answer: (A)

Reliability means the scores are consistent across time, items, or raters, while validity means the test actually measures what it’s intended to measure. A test can produce stable, repeatable results (reliable) but still miss the mark on the construct it’s supposed to assess (not valid). For example, a classroom scale could give the same weight every time, but if it’s biased and doesn’t reflect true weight, it’s reliable yet not valid as a weight measure. This is why a measurement being reliable does not automatically mean it’s valid. Conversely, a test that aims to measure a skill can be valid in that sense but still have some measurement error, so perfect results aren’t guaranteed.

Reliability means the scores are consistent across time, items, or raters, while validity means the test actually measures what it’s intended to measure. A test can produce stable, repeatable results (reliable) but still miss the mark on the construct it’s supposed to assess (not valid). For example, a classroom scale could give the same weight every time, but if it’s biased and doesn’t reflect true weight, it’s reliable yet not valid as a weight measure. This is why a measurement being reliable does not automatically mean it’s valid. Conversely, a test that aims to measure a skill can be valid in that sense but still have some measurement error, so perfect results aren’t guaranteed.