| > If it's so easy, then why do people die from having lesions misdiagnosed as benign? You're confusing False Negatives with True Negatives. For Non-Benign (Positive) vs. Benign (Negative) classification: * True Positive Rate (TPR): non-benign classified as non-benign. * False Positive Rate (FPR): benign misclassified as non-benign. * True Negative Rate (TNR): benign classified as benign. * False Negative Rate (FNR): non-benign misclassified as benign. > It's quite easy to correctly classify 100% of benign cases as benign. You can engineer a 100% TNR if you just classify everything as the "benign" negative class. The FNR is going to be 100% too, but that doesn't matter -- you correctly classified 100% of benign cases as benign. > why do people die from having lesions misdiagnosed as benign? Because the FNR is not 0%. FNR is important. You probably want a decent TPR in there as well. And FPR can be very important too, depending on how life-changing/painful/invasive the treatment for a positive case is! |