Statement 1 : To evaluate a models' performance, we need either precision or recall. Statement 2 : When the v…

Question

Statement 1 : To evaluate a models' performance, we need either precision or recall.
Statement 2 : When the value of both Precision and Recall is 1, the F1 score is 0.

Accepted Answer

## Model Answer **(b) Both statement 1 and statement 2 are incorrect.** Statement 1 is incorrect because both precision **and** recall are needed (combined as F1 score) to fully evaluate a model. Statement 2 is incorrect because when Precision = 1 and Recall = 1, F1 = 2(1×1)/(1+1) = **1**, not 0. ## Explanation - F1 = 2 × (Precision × Recall) / (Precision + Recall). When both = 1, F1 = 1 (perfect score). - Using only precision or only recall gives an incomplete picture; both are needed together for proper evaluation. - Examiners expect you to know the F1 formula and apply it to verify such statements quickly.

Artificial Intelligence — CBSE Class 10 board question