1.3.2—The distinction between precision and accuracy
- Syllabus
- 9702–2028–2029
- Objective
- 1.3.2
- Level
- AS
Precision describes repeatability while accuracy describes closeness to the true value
Precision is the agreement among repeated measurements; accuracy is closeness to an accepted or true value. A result may be precise but inaccurate, or accurate on average but imprecise.
Use repeated readings to assess spread and a reference value or calibration to assess bias. Report uncertainty alongside a measured value.
Readings 10.1,10.1,10.2 are precise; if the true value is 10.8 they are not accurate.
More decimal places do not create accuracy, and averaging removes random scatter but not systematic error.
ConceptA-Level CAIE Physics AS