AUC (area under ROC curve) is an important evaluation criterion, which has been popularly used in many learning tasks such as class-imbalance learning, cost-sensitive learning, learning to rank, etc. Many learning approaches try to optimize AUC, while owing to the non-convexity and discontinuousness of AUC, almost all approaches work with surrogate loss functions. Thus, the consistency of AUC is crucial; however, it has been almost untouched before. In this paper, we provide a sufficient condition for the asymptotic consistency of learning approaches based on surrogate loss functions. Based on this result, we prove that exponential loss and logistic loss are consistent with AUC, but hinge loss is inconsistent. Then, we derive the \textit{$q$-norm hinge loss} and \textit{general hinge loss} that are consistent with AUC. We also derive the consistent bounds for exponential loss and logistic loss, and obtain the consistent bounds for many surrogate loss functions under the non-noise setting. Further, we disclose an equivalence between the exponential surrogate loss of AUC and exponential surrogate loss of accuracy, and one straightforward consequence of such finding is that AdaBoost and RankBoost are equivalent.

本文提供了用于鉴定基于替代损失函数的学习方法渐近一致性的充分条件，并证明了指数损失和逻辑损失与AUC一致，但铰链损失是不一致的。基于这个结果，本文还推导了一些与AUC一致的损失函数，进一步揭示了指数损失和逻辑损失的相容界限以及在非噪声设置下许多替代损失函数的相容界限，并发现AdaBoost和RankBoost具有相同的指数代理损失。

AUC 两两优化的一致性