Uncertainty

Definition

Uncertainty quantifies the doubt about a measurement's accuracy. It indicates the range within which the true value is expected to lie.

5 Must Know Facts For Your Next Test

1. Uncertainty is inherent in all measurements due to limitations in measuring instruments and observer error.
2. Expressing uncertainty involves using significant figures to reflect precision.
3. Systematic errors and random errors are primary sources of uncertainty.
4. Uncertainty can be reduced but never entirely eliminated through improved measurement techniques.
5. The propagation of uncertainty must be considered when combining multiple measurements.

Review Questions

• What are the two main sources of uncertainty in measurements?
• How does one express uncertainty using significant figures?
• Why can uncertainty never be entirely eliminated from measurements?

Related terms

Accuracy: The closeness of a measured value to its true value.

Precision: The consistency of repeated measurements.

Significant Figures: Digits in a measurement that contribute to its precision.