Which term describes the closeness of a set of measurements to each other?

• A. Precision
• B. Accuracy
• C. Calibration
• D. Uncertainty

Answer: (A)

Precision is about how closely repeated measurements agree with one another. It reflects reproducibility: if you measure the same quantity several times and the results cluster tightly, you have high precision. This can happen even if the measurements aren’t close to the true value, which would mean low accuracy. Calibration is the process of adjusting an instrument to match a standard, and uncertainty is the doubt or range around a measurement. For example, multiple measurements yielding values that are very close to each other show high precision, even if that common value isn’t the true quantity. Therefore, the term that describes the closeness of a set of measurements to each other is precision.