arXiv Machine Learning
Oct 16

What Should We Remove? Evaluating the Reliability and Costs of RLVR Data Decontamination

The study audits 16 open RLVR math corpora, totaling 1,673,514 training items, against six benchmarks with 1,949 questions to assess the reliability and data‑loss costs of decontamination policies. Eight policies—based on exact, lexical, and semantic matching—were evaluated using 594 dual‑reviewed training‑benchmark pairs, with calibration and held‑out sets ensuring disjoint benchmark questions and training‑example families. Results show that at a cosine threshold of 0.80, 88% of sampled removals were false, and no semantic threshold in the tested grid met a 90% conservative‑precision target; however, the judge‑adjudicated policy achieved 98.1% resolved precision and 98.2% recall on held‑out corpora, with no confirmed false removals among six sampled removals.

By Esther Xin
arXiv Machine Learning
Sep 18

Model-Aware Data Cleaning for Tabular Foundation Models

The paper introduces L2C‑TFM, a reinforcement‑learning framework for cleaning tabular data before feeding it to Tabular Foundation Models (TFMs). It proposes a model‑aware reward that regularizes the Wasserstein distance between cleaned and dirty data, aiming to preserve distributional stability. Experiments on ten OpenML datasets show that while some reward designs fail, the model‑aware reward performs comparably to a random‑forest baseline and improves minority‑class macro‑F1 under class imbalance, and a policy trained on one dataset can transfer to others.

By Laure Berti-Equille
arXiv AI
Oct 5

Sentence-Level Context Sensitivity as a Training-Free Detector of Unsupported Content, Evaluated Against Trained Verifiers

The paper proposes a training‑free detector that uses sentence‑level context sensitivity to identify unsupported content in retrieval‑augmented generation (RAG) answers. By re‑scoring each sentence with full context, no context, and each chunk removed, the method flags the chunk whose removal most reduces a sentence’s likelihood as the likely source. Evaluated on RAGTruth, TofuEval, and RAGBench, the detector outperforms answer‑level faithfulness scores, achieving AUCs up to 0.745 and matching per‑chunk fact‑checkers while using only a fraction of the compute required by large‑language‑model judges.

By Mohamed Aly Bouke