AUC is the area under a receiver operating characteristic (ROC) curve, which plots sensitivity against the false-positive rate at different thresholds. It summarizes classifier discrimination across those thresholds; a higher AUC indicates better performance. section 5.5.5
For keyword-based review classification, AUC can help assess performance when the decision threshold may vary. It does not remove the need to check sensitivity and specificity: choosing to accept lower specificity should be an informed decision. section 5.5.5











