🤖 AI Summary
Large language models frequently suffer from hallucinations, and existing citation mechanisms are typically coarse-grained, making it difficult to verify fine-grained support relationships between generated content and source evidence—particularly for reasoning-based statements. This work introduces the novel task of fine-grained provenance generation during decoding, requiring models to output sentence-level structured triplets that distinguish among cited, compressed, and inferred evidence. To support this task, we construct ReFInE, an expert-annotated dataset that reveals a significant gap in current models’ ability to trace reasoning steps. We propose a training approach combining supervised fine-tuning (SFT) with Group Relative Policy Optimization (GRPO), using a composite reward to jointly optimize answer faithfulness and provenance accuracy. Our model, GenProve, substantially outperforms 14 strong baselines in joint evaluation, significantly enhancing the verifiability of generated content.
📝 Abstract
Large language models (LLM) often hallucinate, and while adding citations is a common solution, it is frequently insufficient for accountability as users struggle to verify how a cited source supports a generated claim. Existing methods are typically coarse-grained and fail to distinguish between direct quotes and complex reasoning. In this paper, we introduce Generation-time Fine-grained Provenance, a task where models must generate fluent answers while simultaneously producing structured, sentence-level provenance triples. To enable this, we present ReFInE (Relation-aware Fine-grained Interpretability&Evidence), a dataset featuring expert verified annotations that distinguish between Quotation, Compression, and Inference. Building on ReFInE, we propose GenProve, a framework that combines Supervised Fine-Tuning (SFT) with Group Relative Policy Optimization (GRPO). By optimizing a composite reward for answer fidelity and provenance correctness, GenProve significantly outperforms 14 strong LLMs in joint evaluation. Crucially, our analysis uncovers a reasoning gap where models excel at surface-level quotation but struggle significantly with inference-based provenance, suggesting that verifiable reasoning remains a frontier challenge distinct from surface-level citation.