In the context of psychological testing, reliability refers to:

• A. The consistency of test results across time, raters, or items.
• B. The degree to which test scores reflect the theoretical construct.
• C. The accuracy of test norms in representing the population.
• D. The certainty that a test can predict future outcomes.

Answer: (A)

Reliability means a measure is consistent. In psychological testing, that consistency can show up in several ways: the same results when the test is taken again later (test-retest reliability), when different raters score responses in the same way (inter-rater reliability), and when items on a test that are meant to measure the same thing yield similar results (internal consistency). For example, a personality scale would be reliable if someone’s score stays roughly the same on repeated administrations, or if two trained scorers assign similar scores to the same responses, or if the items all hang together to measure the same trait. The other options describe validity aspects—how well the test measures what it’s supposed to measure, how well norms represent a population, or how well the test predicts outcomes. A measure can be reliable without being valid, so reliability is about consistency first and foremost.