Which statement correctly describes the relationship between reliability and validity?

• A. Validity determines reliability.
• B. Reliability is unrelated to validity.
• C. Validity is a condition of reliability.
• D. Reliability is a condition of validity.

Answer: (D)

Reliability is about consistency of measurements, while validity is about whether the measurement actually assesses the intended construct. If results aren’t consistent, you can’t trust what the scores mean, so validity can’t be established. In fact, reliability is a prerequisite for validity: you must have reliable measurements before you can claim they are valid. However, you can have a reliable test that isn’t valid if it consistently measures something else. That’s why the statement that reliability is a condition of validity is the best description of their relationship. The other options misstate the direction or the relationship, or claim independence, which isn’t accurate.