What is AUC?

AUC most commonly refers to Area Under the Curve. In machine learning and statistics, it is frequently used as a performance metric for binary classification models. Specifically, the Area Under the Receiver Operating Characteristic (ROC) curve (AUC-ROC) quantifies the model's ability to distinguish between positive and negative classes across various classification thresholds. A higher AUC score indicates better performance. It is also sometimes used in other fields such as pharmacokinetics (AUC representing drug exposure) but its primary association is in machine learning model evaluation.