Repeats and averaging improve which aspect of measurement?

• A. Precision
• B. Accuracy
• C. Resolution
• D. Range

Answer: (A)

Repeating measurements and averaging target random fluctuations in the readings. When you measure something multiple times, each result jitteres around the true value due to unpredictable influences. By averaging all the measurements, these random errors tend to cancel out, so the reported value becomes more reproducible from one set of measurements to another. That quality—how consistent repeated measurements are with each other—is called precision.

Keep in mind that averaging doesn’t fix a systematic bias in the instrument or method. If there’s a consistent error that shifts every reading in the same direction, averaging won’t remove it, so accuracy (how close you are to the true value) wouldn’t improve. Also, the ability to discern smaller details (resolution) or the total span you can measure (range) aren’t changed by averaging; those depend on the instrument’s design and scale. A useful pointer is that the uncertainty of the mean typically shrinks with more repeats, roughly proportional to 1 over the square root of the number of measurements.