F1 Score
درجة F1
Also known as: F-measure
F1 score is the harmonic mean of precision and recall: 2·(P·R)/(P+R). It penalizes lopsided models — one that catches everything but cries wolf, or one that is silent but always right. F1 is the right headline metric when classes are imbalanced (rare violations vs. compliant frames in PPE), because plain…
Definition
F1 score is the harmonic mean of precision and recall: 2·(P·R)/(P+R). It penalizes lopsided models — one that catches everything but cries wolf, or one that is silent but always right. F1 is the right headline metric when classes are imbalanced (rare violations vs. compliant frames in PPE), because plain accuracy gets misleadingly high by predicting the majority class. FI Tech contracts include F1 thresholds per class: hard-hat ≥ 0.95, harness ≥ 0.88, glasses ≥ 0.85. The macro-F1 (mean across classes) appears on every customer dashboard.
