Precision and recall

Precision or positive predictive value is a measure for exactness and recall or sensitivity is a measure of completeness. They range from 0 to 1 and the best possible value for both of them is 1.

$\text{precision} = \frac{tp}{tp + fp}$

$\text{recall} = \frac{tp}{tp + fn},$

where $tp$ is the number of true positives, $fp$ the number of false positives, and $fn$ the number of false negatives.

External links

• Wikipedia: Precision and recall