Precision

Definition

Precision refers to the consistency of a set of measurements or results. It indicates how close the measurements are to each other, regardless of their accuracy.

5 Must Know Facts For Your Next Test

1. Precision is not the same as accuracy; precision focuses on consistency, while accuracy focuses on correctness.
2. High precision means repeated measurements yield very similar results.
3. Precision is often represented by the standard deviation or range of the data set.
4. Instruments with high precision will have minimal variation in their readings under unchanged conditions.
5. Precision can be affected by systematic errors but not random errors.

Review Questions

• What does it mean for a measurement to be precise?
• How can you determine if a set of measurements is precise?
• Is it possible for a measurement to be precise but not accurate? Explain with an example.

Related terms

Accuracy:

The closeness of a measured value to a standard or known value.

Measurement Uncertainty: An estimate of the amount by which the measured value may differ from the true value.

Standard Deviation:

A measure of the amount of variation or dispersion in a set of values.