# F1-Measure

(Redirected from F1)

An F1-Measure is an F-measure where the β is equal to 1.

**AKA:**[math]F_1[/math].**Context:****Counter-Example(s):**- an F2-Measure.
- an F0.5-Measure.

**See:**Harmonic Mean.

## References

### 2011

- (Sammut & Webb, 2011) ⇒ Claude Sammut (editor), and Geoffrey I. Webb (editor). (2011). “F1-Measure.” In: (Sammut & Webb, 2011) p.397
- (Wikipedia, 2011) ⇒ http://en.wikipedia.org/wiki/F1_score
- QUOTE:In statistics, the
**F**(also F-score or_{1}score**F-measure**) is a measure of a test's accuracy. It considers both the precision*p*and the recall*r*of the test to compute the score:*p*is the number of correct results divided by the number of all returned results and*r*is the number of correct results divided by the number of results that should have been returned. The F_{1}score can be interpreted as a weighted average of the precision and recall, where an F_{1}score reaches its best value at 1 and worst score at 0.The traditional F-measure or balanced F-score (F

_{1}score) is the harmonic mean of precision and recall: :[math]F = 2 \cdot \frac{\mathrm{precision} \cdot \mathrm{recall}}{\mathrm{precision} + \mathrm{recall}}[/math].

- QUOTE:In statistics, the