Compute the F1 score for pneumonia and mass separately based on the following retrieved labels and ground truth:

Question

topGrad Admin · Accepted Answer

Explanation: Let’s begin with pneumonia. Both precision and recall are 0.5. Therefore the F1 score is 2*0.5*0.5 / (0.5 + 0.5) = 0.5. Next let’s do mass. Recall was 2/3, while precision was 1. Computing the F1 score, we get 2*⅔*1 / (1 + 2/3) = 0.8. Therefore the correct answer is B. A was using the arithmetic mean, so be careful!