Accuracy

Definition

The degree to which a measurement, estimate, or observation approximates the true value of the quantity being measured; a systematic measure of correctness as opposed to the random scatter captured by precision. In biological research, accuracy reflects freedom from systematic error (bias), whether in morphometric data, population census techniques, or experimental assays.

Etymology

From Latin accuratus, 'done with care,' from ad- 'to' + curare 'to take care.'

Example

A pitfall trap array that consistently underestimates ground beetle abundance because traps are emptied too infrequently lacks accuracy, even if repeated sampling yields highly consistent (precise) counts; conversely, a calibrated light trap that captures the true proportional representation of local moth species demonstrates accuracy.

Synonyms

• trueness

Related Terms

• Precision
• systematic error
• Bias
• calibration
• measurement error
• validity
• reliability

Usage Notes

Accuracy and precision are frequently conflated but are orthogonal properties: accurate measurements may be imprecise (scattered around the true value), and precise measurements may be inaccurate (consistently offset from the true value). In field biology, accuracy often depends on proper instrument calibration, representative sampling design, and correction for detection probability—issues distinct from the repeatability that defines precision. When reporting morphological data or ecological estimates, authors should specify accuracy assessments (e.g., through known standards or validation against independent methods) separately from precision estimates (e.g., standard deviations or confidence intervals).