F-Score

Definition

F1 Score

$F_1=\frac{2}{{\text{recall}}^{-1}+{\text{precision}}^{-1}}=2\frac{\text{precision}\cdot \text{recall}}{\text{precision}+\text{recall}}$ The harmonic mean of Precision and Recall.

F-beta score

$F_{\beta }=(1+{\beta }^2)\frac{\text{precision}\cdot \text{recall}}{({\beta }^2\cdot \text{precision})+\text{recall}}$ where $\beta >0$

Recall is considered $\beta$ times as important as Precision.