arXiv Computation and Language

HyperProve: Answer-Guided Hypergraph Expansion for Multi-Hop Question Answering

arXiv Computation and Language
Aug 25

GTA-RAG: Graph-Trajectory-Augmented Reinforcement Learning for Multi-Turn Retrieval-Augmented Reasoning

arXiv:2608.22479v1 Announce Type: new Abstract: Retrieval-augmented generation (RAG) enables LLMs to access external knowledge for answering knowledge-intensive questions. For complex multi-hop quest...

By Jun Chen, Yongchao Liu, Pengyu Qiu, Jiajun Zheng, Juelu Zhang, Yujie Zeng, Qin Zhang, Ziyue Qiao, Xiao Luo
arXiv Computation and Language
Aug 31

PRISM: Agentic Retrieval with LLMs for Multi-Hop Question Answering

PRISM is an agentic retrieval framework that uses large language models in a structured loop to improve evidence gathering for multi‑hop question answering. It splits retrieval into three specialized agents—a Question Analyzer, a Selector focused on precision, and an Adder focused on recall—whose iterative interaction yields a compact yet comprehensive evidence set. Experiments on HotpotQA, 2WikiMultiHopQA, MuSiQue, and MultiHopRAG show that PRISM consistently outperforms strong baselines by achieving higher retrieval accuracy and filtering out distracting content.

By Md Mahadi Hasan Nahid, Davood Rafiei
arXiv Computation and Language
Oct 22

Graph Topology Meets Energy-Driven Pathfinding: Preserving Contextual Consistency in Retrieval-Augmented Generation

ThreadRAG is a retrieval‑augmented generation framework that preserves contextual consistency by structuring retrieved documents into Semantic Nodes and building a Semantic Topology Graph (STG). It uses Energy‑Driven Pathfinding (EDP) to identify query‑relevant subgraphs and linearize them into coherent textual evidence paths. Experiments on HotpotQA, 2WikiMultihop, and another benchmark show ThreadRAG outperforms strong baselines, achieving a 14.4% EM gain on HotpotQA and a 5.8% EM lead on 2WikiMultihop while cutting token cost to 23.3% of the strongest baseline.

By Yufeng Li, Zaijing Li, Fuchen Zhang, Zongzong Wu, Ming Zhao, Fengxiao Tang
arXiv AI
Sep 16

Diagnosing the Fact-Grounding Gap in Multi-Hop Question Answering

The paper investigates multi‑hop question answering systems and identifies two distinct failure modes: retrieval failures, where the necessary passage is not retrieved, and extraction failures, where the passage is retrieved but the required fact cannot be extracted—a phenomenon termed the fact‑grounding gap. Across three standard benchmarks, extraction failures account for nearly half of all per‑hop deficiencies and are invisible to standard retrieval metrics, remaining unresolved by retrieval‑only interventions. The study shows that these two bottlenecks require different solutions, a distinction currently missing from evaluation practices.

By Kevin Mo, Nathan Mo, Richard Zhu
arXiv Computation and Language
Sep 1

Hi-Q: Hierarchical Evidence-guided Query Refinement for Multi-Hop Question Answering

Hi-Q is a new framework for multi‑hop question answering that refines queries hierarchically based on evidence retrieved from a corpus. At each node it tests whether the current query unit is supported by evidence; if not, the node is expanded using a dependency‑preserving binary operator and verified for semantic coverage. The resulting query tree grows according to corpus support signals, and Hi‑Q achieves state‑of‑the‑art performance on three multi‑hop QA benchmarks, outperforming both iterative retrieval and graph‑based baselines without constructing a corpus‑wide graph.

By Jueun Kim, Sungho Park, Wook-Shin Han
arXiv AI
Oct 16

CARA: Causally Guided Retrieval Agent for Question Answering

CARA is a training‑free, causally guided retrieval agent designed for question answering over text‑rich knowledge graphs. It evaluates retrieved evidence using two causal criteria—consequentiality and essentiality—alongside path consistency, and aggregates results from multiple agents via reciprocal rank fusion. Experiments on three STaRK datasets show that CARA outperforms existing retrievers, improving answer quality and faithfulness while examining fewer graph nodes and requiring fewer retrieval operations.

By Weicheng Liu, Xiangcheng Wu, Depeng Xu, Haopeng Zhang, Xi Niu