# AQA Science: Glossary - Accuracy

A measurement result is considered accurate if it is judged to be close to the true value.

e.g. Bob, Bill and Becky are asked to determine the capacity of a box for storing ball bearings. Each of them uses a different ruler and only one takes care doing it. Here are their results:

NameWidth (cm)Height (cm)Depth (cm)Capacity (cm³)
Bob1097630
Bill1186.5572
Becky10.87.96.4546

The true value of the capacity is 545 cm³, so Becky's measurements are the most accurate. Her calculated capacity is the most accurate.

## Quoting Accuracy

You may also need to indicate how accurate an answer is (called uncertainty).

e.g. the speed of a wave on a string is 34.5 m/s within 0.5 m/s.

We would often write this as 34.5 ± 0.5 m/s
where the ± symbol means "plus or minus". Read more.

 Accuracy Calibration Data Errors* Evidence Fair test Hypothesis Interval Precision Prediction Range Repeatable Reproducible Resolution Sketch Graph True Value Uncertainty Validity Valid Conclusion Variables* * These terms have a number of related items.

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