**Precision(P) and Recall(R)
**


Manual Annotation/Oracle/Ground Truth(X Axis)
\\ System Output(Y Axis)     



|              ^ Yes                  ^ No                 ^
^ Yes          | True Positive(TP)    | False Positive(FP) |
^ No           | False Negative(FN)   | True Negative(TN)  |



P= TP/(TP+FP)

R= TP/(TP+FN)

F= 1/(1/P + 1/R)<sup>1/2</sup>
 = 2PR/(P + R)