arXiv AI

Divide et Calibra: Multiclass Local Calibration via Vector Quantization

arXiv Machine Learning
Oct 9

V-ECE: Estimating General Expected Calibration Errors

The paper introduces V-ECE, a variational estimator for general Expected Calibration Errors (ECE) that avoids binning and works with any convex divergence, including Lp distances. By using prediction‑dependent proper scores and a residual‑fitted temperature scaling via gradient boosting, V‑ECE provides a lower‑bound estimate of true calibration error. Experiments on semi‑synthetic benchmarks show V‑ECE outperforms existing binary and multiclass estimators, with additional theoretical insights on bias and confidence estimation.

By Eug\`ene Berta, Sacha Braun, Francis Bach, Michael I. Jordan, David Holzm\"uller
arXiv Computer Vision
Oct 23

Residual Calibration via Local Feature-Space Refinement

The paper introduces Local Adaptive Probability Estimation (LAPE), a post‑hoc residual calibration framework that refines global calibrator outputs using non‑parametric local evidence from neighboring samples in feature space. LAPE serves as a plug‑and‑play module that leverages feature‑space geometry and reuses calibration data, improving calibration quality for various baselines. The authors also extend the approach to multi‑view inputs with Cascade Feature Augmentation Fusion (CFAF) and demonstrate its effectiveness through extensive experiments.

By Xihao Wang, Chengyao Yu, Ruixing Ming
arXiv AI
Jul 28

DecoupleMix: Decoupled Ratio Search and Convex Allocation for Scalable VLM Data Recipes

arXiv:2607. 24516v1 Announce Type: cross Abstract: While data curation for Vision Language Models (VLMs) is increasingly active, public practice for constructing pretraining mixtures remains largely heuristic: practitioners stack datasets that pass quality filters, set cross-domain ratios by intuition, and lack a principled, attributable criterion for admitting new data, while frontier recipes remain undisclosed.

By Jiahao Xie, Zhongbin Guo, Qianle Wang, Ruiqi Lu, Dongling Xiao, Wanxuan Sun, Cheng Yang
arXiv Machine Learning
Oct 23

Is High Local Accuracy Enough? Geometric Consensus with Support-Adaptive Statistical Personalization for Federated Learning

The paper introduces FedGRC, a federated learning framework that enhances both global recognition and personalization for heterogeneous clients. It combines Consensus‑Guided Representation Learning, Multilayer Metric Synthesis, and Support‑Adaptive Shrinkage Personalization to address failures on rare or unseen classes. Experiments on CIFAR‑10, CIFAR‑100, and the FedRS dataset show that FedGRC outperforms 21 baseline methods, improving global accuracy and personalization floors by over 2% in several settings.

By Junyu Lin, Bosong Qi, Pengcheng Shi, Jiayuan Li
arXiv AI
Oct 12

Calibration in One Go: Jointly Learning Accurate and Calibrated Neural Networks

The paper proposes a bilevel Stackelberg formulation that trains standard post‑hoc calibrators end‑to‑end with the neural network backbone, eliminating the need for a separate calibration dataset or dedicated loss. By jointly optimizing accuracy and calibration with cross‑entropy and a single calibrator learning‑rate hyperparameter, the method can use any calibrator type, but shows that the final classification layer alone suffices to produce accurate, well‑calibrated models. This approach outperforms state‑of‑the‑art calibrators while adding minimal complexity and avoiding the overhead of separate calibration components, especially beneficial in multi‑task learning settings.

By Nektarios Kalampalikis, Pablo M. Olmos, Isabel Valera
arXiv Machine Learning
Sep 10

Learning Kernels by Alignment for Multiclass Bayes Classification

The paper introduces a framework that learns the kernel used in kernel methods through alignment, leveraging the Collaborative Learning and Inference (CLaI) approach. It demonstrates that CLaI can be interpreted as a kernel alignment process and that its inference stage is equivalent to kernel Bayes classification with Parzen-window density estimation. By replacing cosine similarity with a learned Mahalanobis distance, the authors extend CLaI to multiclass classification, achieving higher accuracy, faster convergence, and lower calibration error on datasets such as CIFAR-10, PathMNIST, and SleepEDF, while also showing connections to Gaussian processes and competitive calibration in sepsis prediction.

By Hollan Haule, Alfredo Gonzalez-Sulser, Javier Escudero