arXiv Machine Learning By Tobias Brock, Thomas Nagler

Fast Rates for Nonstationary Weighted Risk Minimization

Read the original on arXiv Machine Learning →

The paper investigates weighted empirical risk minimization under nonstationary data, decomposing the excess risk into a learning component and a drift component. It establishes oracle inequalities for the learning error under mixing conditions, uniformly over arbitrary weight classes, and derives explicit bounds for drift errors in square loss settings, covering structural‑break and smoothly drifting processes. The analysis is extended to auto‑regression problems with linear models, basis approximations, and neural networks, revealing that optimal weights balance learning and drift via a bias–variance trade‑off and recover minimax‑optimal rates in unweighted, stationary cases.

Machine-generated by The Flow from the publisher's headline and feed description — not written or checked by a human. The full article lives at arXiv Machine Learning.

arXiv Statistics ML
Oct 12

Beyond Discrepancy: Oracle Drift in Nonstationary Weighted Risk Minimization

The paper studies distributional drift in nonstationary weighted risk minimization by breaking down excess risk into estimation, drift, and approximation parts. It argues that traditional discrepancy-based bounds are often overly conservative because they can scale larger than the actual excess-risk contribution and react to risk surface changes that do not affect the optimal predictor. The authors provide a tighter oracle drift bound, analyze its behavior in parametrized regression models—particularly linear regression—and extend the results to nonparametric regression.

By Tobias Brock, Thomas Nagler
arXiv Machine Learning
Sep 11

General Quantification of Covariate and Concept Shifts

arXiv:2609. 11918v1 Announce Type: new Abstract: Generalization under distribution shift remains a core challenge in modern machine learning, yet existing learning bound theory is limited to narrow, idealized settings and is non-estimable from samples.

By Hongbo Chen, Li Charlie Xia