Accuracy and precision


Written By: Ehsan Jahandarpour

Accuracy and precision are two measures of observational error. Accuracy is how close or far off a given set of measurements (observations or readings) are to their true value, while precision is how close or dispersed the measurements are to each other. In other words, precision is a description of random errors, a measure of statistical variability. Accuracy has two definitions: In the first, more common definition of “accuracy” above, the concept is independent of “precision”, so a particular set of data can be said to be accurate, precise, both, or neither.