Reliability versus validity: which statement correctly describes these concepts in measurement data?

• A. Reliability refers to consistency of data collection; validity refers to whether data accurately measure the intended construct.
• B. Reliability means data are valid; validity means data are precise.
• C. Reliability relates to cost; validity relates to speed.
• D. Reliability and validity are the same thing.

Answer: (A)

Reliability is about consistency of measurements across time, items, or raters. If you measure the same thing under the same conditions, you should get the same result. Validity is about accuracy: does the instrument actually measure the concept you intend to measure?

So, a measurement can be consistently off (reliable but not valid), or it could be valid in what it aims to capture but produce varying results if it isn’t reliable. The statement that links reliability to consistency and validity to accuracy correctly distinguishes the two.

The other options mix up these ideas or introduce unrelated factors like cost or speed, or claim they are the same, which doesn’t fit how reliability and validity are defined in measurement.