Usmile likelihood evaluation provides robust threshold free assessment of binary classification models for balanced and imbalanced datasets
摘要
Current metrics for binary classification, like the Area Under the Receiver Operating Characteristic curve (AUC-ROC) or Log Loss, provide a global performance score. However, they do not quantify predictive quality separately for event and non-event classes. This limitation is particularly critical in imbalanced settings like medical diagnostics. To address it, we introduce the U-smile Likelihood Evaluation (LE) method, a substantial extension of the original U-smile framework. The U-smile LE method is based on a new metric called the relative Likelihood Ratio (rLR). This single score measures overall model strength without needing a classification threshold. We decompose this score into two class-specific components: