EvidenceRL: Reinforcing Evidence Consistency for Trustworthy Language Models

Fuente: arXiv
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Main Authors: Tamo, J. Ben, Lu, Yuxing, Marteau, Benoit L., Nnamdi, Micky C., Wang, May D.
Format: Preprint
Published: 2026
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author Tamo, J. Ben
Lu, Yuxing
Marteau, Benoit L.
Nnamdi, Micky C.
Wang, May D.
author_facet Tamo, J. Ben
Lu, Yuxing
Marteau, Benoit L.
Nnamdi, Micky C.
Wang, May D.
contents Large Language Models (LLMs) are fluent but prone to hallucinations, producing answers that appear plausible yet are unsupported by available evidence. This failure is especially problematic in high-stakes domains where decisions must be justified by verifiable information. We introduce \textbf{EvidenceRL}, a reinforcement learning framework that enforces evidence adherence during training. EvidenceRL scores candidate responses for grounding (entailment with retrieved evidence and context) and correctness (agreement with reference answers) and optimizes the generator using Group Relative Policy Optimization (GRPO). We evaluate across two high-stakes domains, cardiac diagnosis and legal reasoning, where EvidenceRL consistently improves evidence grounding and faithfulness without sacrificing task accuracy. On cardiac diagnosis, F1@3 increases from 37.0 to 54.5 on Llama-3.2-3B while grounding ($G_{\max}@3$) rises from 47.6 to 78.2; hallucinations drop nearly 5$\times$ and evidence-supported diagnoses increase from 31.8\% to 61.6\%. On legal reasoning, EvidenceRL raises Faithfulness from 32.8\% to 67.6\% on Llama-3.1-8B, demonstrating consistent behavioral change across domains. Our code is open-sourced at https://github.com/Wizaaard/EvidenceRL.git.
format Preprint
id arxiv_https___arxiv_org_abs_2603_19532
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle EvidenceRL: Reinforcing Evidence Consistency for Trustworthy Language Models
Tamo, J. Ben
Lu, Yuxing
Marteau, Benoit L.
Nnamdi, Micky C.
Wang, May D.
Computation and Language
Information Retrieval
Machine Learning
Large Language Models (LLMs) are fluent but prone to hallucinations, producing answers that appear plausible yet are unsupported by available evidence. This failure is especially problematic in high-stakes domains where decisions must be justified by verifiable information. We introduce \textbf{EvidenceRL}, a reinforcement learning framework that enforces evidence adherence during training. EvidenceRL scores candidate responses for grounding (entailment with retrieved evidence and context) and correctness (agreement with reference answers) and optimizes the generator using Group Relative Policy Optimization (GRPO). We evaluate across two high-stakes domains, cardiac diagnosis and legal reasoning, where EvidenceRL consistently improves evidence grounding and faithfulness without sacrificing task accuracy. On cardiac diagnosis, F1@3 increases from 37.0 to 54.5 on Llama-3.2-3B while grounding ($G_{\max}@3$) rises from 47.6 to 78.2; hallucinations drop nearly 5$\times$ and evidence-supported diagnoses increase from 31.8\% to 61.6\%. On legal reasoning, EvidenceRL raises Faithfulness from 32.8\% to 67.6\% on Llama-3.1-8B, demonstrating consistent behavioral change across domains. Our code is open-sourced at https://github.com/Wizaaard/EvidenceRL.git.
title EvidenceRL: Reinforcing Evidence Consistency for Trustworthy Language Models
topic Computation and Language
Information Retrieval
Machine Learning
url https://arxiv.org/abs/2603.19532