Test-retest reliability assesses?

• A. Consistency of measurements across time by the same individual
• B. Agreement between two different raters
• C. Content validity
• D. Face validity

Answer: (A)

Consistency of measurements over time for the same person is what test-retest reliability evaluates. It checks whether a measurement yields similar scores when the same individual takes the same test on two different occasions, assuming the underlying trait hasn’t genuinely changed and the testing conditions are comparable. A high level of stability between the two sets of scores indicates that the instrument is reliable over time and that observed scores aren’t just random fluctuations or measurement error.

This differs from other reliability concepts: agreement between two raters is about consistency across different evaluators, not across time; and validity concepts like content validity and face validity address whether the test actually measures the intended construct and appears to do so, rather than whether it remains stable on repeated administrations.