Which term describes the closeness of repeated results (reproducibility)?

• A. Accuracy
• B. Inaccuracy
• C. Precision
• D. Imprecision

Answer: (C)

Precision describes the closeness of repeated results. In laboratory quality control, it means how tightly a set of measurements of the same sample agree with each other when you repeat the test under the same conditions. High precision shows little scatter among results, while low precision shows more variability. This is distinct from accuracy, which asks how close those measurements are to the true value. A method can be precise (consistent results) but not accurate (off from the true value), or accurate but not precise (results cluster around the true value but vary widely). Terms like imprecision or inaccuracy describe lack of precision or lack of closeness to the true value, respectively, but the standard term for repeated-result consistency is precision. Reproducibility extends precision across different conditions, such as different days, operators, or instruments.