Uncertainty

Definition

Uncertainty in measurements is the range within which the true value is expected to lie. It reflects the limitations of measurement instruments and methods.

5 Must Know Facts For Your Next Test

1. Uncertainty is often represented as a ± value following a measurement, indicating the possible deviation from the measured value.
2. The uncertainty can be influenced by factors like instrument precision, calibration errors, and environmental conditions.
3. In chemistry, significant figures are used to express the precision of measurements and inherently include uncertainty.
4. Measurement uncertainty affects both accuracy (closeness to the true value) and precision (reproducibility) of data.
5. Reporting uncertainties is crucial for scientific communication as it provides context for how reliable and accurate results are.

Review Questions

• How is measurement uncertainty typically represented in scientific notation?
• What factors can influence the uncertainty of a measurement?
• Why is it important to report uncertainties in scientific results?

Related terms

Accuracy: The degree to which a measured value agrees with the true or accepted value.

Precision: The degree to which repeated measurements under unchanged conditions show the same results.

Significant Figures: Digits in a measurement that are known with certainty plus one digit that is estimated, reflecting its precision.