F1 Score

From Wikipedia, the free encyclopedia

Sometimes called F-score or F-measure.

In statistics, the F1 Score is a measure of a test's accuracy. It is defined as 2pr/(p+r), where p is the precision and r is the recall of the test. The F1 score can be easily computed by finding p as the number of correct results divided by the number of all returned results and r as the number of correct results divided by the number of results that should have been returned. The F1 score can be interpreted as a weighted average of the precision and recall, where an F1 score reaches its best value at 1 and worst score at 0.