The consistency of a measurement across trials and investigators is known as which term?

• A. Dependability
• B. Vulnerability
• C. Reliability
• D. Validity

Answer: (C)

Reliability is the consistency of a measurement across trials and investigators. It means that if you repeat the measurement under the same conditions, you should get similar results, and if different researchers take the measurement, their scores should align. This includes ideas like test-retest reliability (stability over time) and inter-rater reliability (agreement between observers). It’s different from validity, which asks whether the instrument actually measures what it’s intended to measure; a measure can be reliable (consistent) without being valid (accurate). While dependability is sometimes used in everyday language, the standard term for this scientific property is reliability. Vulnerability isn’t a related measurement property.