Reliability refers to ...

• A. The consistency of results across items or administrations
• B. The accuracy with which a measure assesses what it intends to measure
• C. The generalizability to other populations
• D. The magnitude of relationships with other measures

Answer: (A)

Reliability is about consistency in measurement. It means a test or instrument yields similar results when conditions are kept steady, whether that’s across different items within the test (internal consistency) or across multiple administrations or forms (test-retest or alternate forms). This focus on stability distinguishes reliability from other concepts that deal with accuracy or applicability. For example, a scale that shows the same weight every time you step on it demonstrates reliability. But reliability doesn’t guarantee that the measurement is accurate; it could be consistently off if the scale is biased. Concepts like validity look at whether the test measures what it’s supposed to measure, generalizability concerns applying findings to other groups, and the strength of relationships with other measures speaks to validity evidence rather than consistency.