Cross-Validation Is All You Need: A Statistical Approach To Label Noise Estimation
Jianan Chen, Vishwesh Ramanathan, Tony Xu, Anne L. Martel
TL;DR
The paper addresses label noise in supervised learning, particularly in medical settings, by observing that cross-validation fluctuations across folds can reflect noisy labels and thus be informative for detection. It introduces ReCoV, a model-agnostic, parameter-free detector, and fastReCoV, a scalable variant, that identify noisy samples by tracking which samples repeatedly appear in the worst-performing folds during repeated $k$-fold cross-validation and related Monte-Carlo analyses. The methods are validated across binary (Mushroom), multi-class (CIFAR-10N), survival (HECKTOR), and regression (PANDA) tasks, achieving state-of-the-art noise-detection performance and improving retrained model accuracy, including survival-model concordance-index improvements. The work provides practical, plug-in tools for data cleaning in diverse domains and suggests potential applicability to medical foundation-model workflows.
Abstract
Machine learning models experience deteriorated performance when trained in the presence of noisy labels. This is particularly problematic for medical tasks, such as survival prediction, which typically face high label noise complexity with few clear-cut solutions. Inspired by the large fluctuations across folds in the cross-validation performance of survival analyses, we design Monte-Carlo experiments to show that such fluctuation could be caused by label noise. We propose two novel and straightforward label noise detection algorithms that effectively identify noisy examples by pinpointing the samples that more frequently contribute to inferior cross-validation results. We first introduce Repeated Cross-Validation (ReCoV), a parameter-free label noise detection algorithm that is robust to model choice. We further develop fastReCoV, a less robust but more tractable and efficient variant of ReCoV suitable for deep learning applications. Through extensive experiments, we show that ReCoV and fastReCoV achieve state-of-the-art label noise detection performance in a wide range of modalities, models and tasks, including survival analysis, which has yet to be addressed in the literature. Our code and data are publicly available at https://github.com/GJiananChen/ReCoV.
