Jiale Xing

Author directory

2026

Retrieval-Augmented Generation (RAG) improves model factuality, but multi-hop question answering still suffers from incomplete and disconnected evidence retrieval across documents or chunks. Although graph-enhanced RAG methods organize evidence with graphs or hypergraphs, existing structures still struggle to balance the completeness of higher-order factual structures with fine-grained evidence connectivity. Graph-based methods mainly rely on pairwise edges and may fail to preserve complex multi-entity facts, while hypergraph-based methods can capture higher-order contexts but may underuse low-order relations for step-by-step evidence tracing. Both types of methods may further suffer from evidence fragmentation when semantically equivalent entity mentions are not effectively organized across chunks. To address these issues, we propose HEAR-RAG, a hypergraph-based evidence-aware retrieval framework for multi-hop question answering. HEAR-RAG organizes distributed evidence into a unified factual evidence hypergraph that jointly preserves higher-order factual contexts, low-order relational clues, and source chunks. It further introduces relation-aware entity mention clustering to reduce evidence fragmentation, and uses hybrid structural retrieval to construct connected evidence paths for answer generation. Experiments on multiple multi-hop QA benchmarks demonstrate its effectiveness.