arXiv Machine Learning

CRISP: Scalable Importance-Stratified Coresets for Imbalanced Tabular Learning

CRISP (Coreset Reduction via Importance-Stratified Pruning) is a linear-time method that reduces negative-class examples in highly imbalanced tabular datasets by allocating a budget across quantile strata of a proxy-model score and using sample weights to correct for unequal inclusion probabilities. On a production fraud dataset, CRISP cuts the training set from 25 M to about 1.70 M rows (a 93.2% reduction) while preserving 99.7% of the full-data Average Precision. In public benchmarks such as CriteoPrivateAds, CRISP consistently achieves the highest mean Average Precision across a range of majority reductions, with ablation studies highlighting budget allocation and inverse-propensity weighting as key contributors to its performance.

arXiv Machine Learning
Sep 22

Are Coreset Selection Methods Worth Their Cost?

The paper evaluates coreset selection methods by incorporating both selection and training time into a unified wall‑clock budget, using a standardized benchmark across four datasets and multiple selectors. Across numerous budget anchors, simple random or full‑data training consistently outperforms sophisticated selectors, and selection costs are dominated by a full‑dataset scan that cannot be amortized. The study also identifies when subset reuse can justify selection and reports several correctness fixes in a popular codebase.

By Yangze Liu, Zhongyi Han
arXiv Machine Learning
5d ago

Tabular Imbalanced Learning: A Survey, Benchmark, and Practical Guide

The paper surveys tabular imbalanced learning and introduces TILBench, a benchmark evaluating over 40 methods on 57 datasets. It presents a unified taxonomy of approaches and shows that no single method dominates across all settings, with performance depending on dataset regimes and computational constraints. Practical recommendations for method selection and future research directions are provided.

By Ruizhe Liu, Jiaqi Luo
arXiv Machine Learning
Jul 30

Cost-Sensitive Conformal Prediction and Human-in-the-Loop Abstention for Imbalanced High-Stakes Decision Support: A Multi-Domain Benchmark

arXiv:2607. 27143v1 Announce Type: new Abstract: High-stakes decision systems in credit scoring, fraud detection, healthcare, and industrial safety require reliable uncertainty quantification under severe class imbalance and asymmetric error costs.

By Manpreet Singh, Akshatha Srikantha, Shyamal Lakhanpal
arXiv Machine Learning
1d ago

The Hidden Costs of 99% Accuracy: A Trustworthiness Audit of the Telco Customer Churn Benchmark

The paper audits the IBM Telco Customer Churn benchmark, revealing that common practices inflate performance metrics. It shows that pre‑split SMOTE boosts churn‑class F1 by 13.1 points, that isotonic regression is the best calibration method while temperature scaling fails on tree ensembles, and that the cost‑optimal decision threshold is 5–10 times lower than the F1‑optimal one, saving about $77,000 per 1,000 customers. The authors also test generalisation on Iranian Telecom and Bank churn datasets, and propose a four‑component reporting checklist with reproducible code.

By Soumyadeep Roy