| English | Accuracy |
|---|---|
| Bahasa Melayu | Kejituan |
| 中文 | 准确度 |
Definition
How close a measured value is to the true or accepted value of a quantity.
In exam terms
Accuracy tells you how close a measured value is to the true or accepted value of a quantity. It is a description of quality, not a physical quantity itself, so it has no symbol and no SI unit; you describe it as high or low, or express it using relative error.
Accuracy is improved by removing systematic errors such as a zero error, using a correctly calibrated instrument, and reading at eye level to avoid parallax. For example, if the true mass of a block is 100.0 g and a balance reads 100.1 g, the reading is accurate because it is very close to the true value.
Do not confuse it with precision
Do not confuse accuracy with precision. Accuracy is closeness to the true value; precision is how closely repeated readings agree with each other.
A set of readings can be very precise (tightly grouped) yet inaccurate if there is a zero error shifting them all away from the true value.
In Paper 2 this is often asked as state the difference between accuracy and precision, or suggest one way to improve the accuracy of the experiment (answer: check and correct the zero error, or repeat and take the average).
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)