Training neural network classifiers on datasets with label noise poses a risk of overfitting them to the noisy labels. To address this issue, researchers have explored alternative loss functions that aim to be more robust. However, many of these alternatives are heuristic in nature and still vulnerable to overfitting or underfitting. In this work, we propose a more direct approach to tackling overfitting caused by label noise. We observe that the presence of label noise implies a lower bound on the noisy generalised risk. Building upon this observation, we propose imposing a lower bound on the empirical risk during training to mitigate overfitting. Our main contribution is providing theoretical results that yield explicit, easily computable bounds on the minimum achievable noisy risk for different loss functions. We empirically demonstrate that using these bounds significantly enhances robustness in various settings, with virtually no additional computational cost.

训练神经网络分类器在带有标签噪声的数据集上存在过拟合的风险，为了解决这个问题，研究人员探索了更加稳健的替代损失函数，然而，许多这些替代方法都是启发式的，仍然容易受到过拟合或欠拟合的影响。在本研究中，我们提出了一种更直接的方法来应对标签噪声引起的过拟合问题，我们观察到标签噪声的存在意味着噪声泛化风险的下界，基于这一观察，我们提出在训练过程中对经验风险施加一个下界来减轻过拟合问题。我们的主要贡献是提供了理论结果，给出了不同损失函数下噪声风险的最小可达下界的明确、易于计算的界限。我们通过实验证明，在各种设置中使用这些界限极大地提高了鲁棒性，几乎没有额外的计算成本。

标签噪声：纠正一次修正