Chain-of-Relations: Faithful and Efficient LLM Reasoning over Knowledge Graphs via Relation-Centric Exploration

摘要

Knowledge graph question answering (KGQA) serves as an essential benchmark for KG-enhanced large language models. Among various approaches, agent-based methods have emerged as an effective solution.Existing methods adopt entity-centric exploration that incrementally constructs reasoning paths by selecting and connecting intermediate entities. However, they face two critical limitations. (1) Entity incompleteness vulnerability arises when some intermediate entities lack semantic information beyond opaque IDs, preventing relevance evaluation and leading to discarding valid reasoning paths.(2) Premature entity pruning occurs because beam search retains only top-ranked entities at each step, eliminating candidates before their relevance can be verified.To address these challenges, this paper proposes Chain-of-Relations (CoR) with relation-centric exploration and global entity filtering, reducing dependence on entity completeness and ensuring complete candidate retrieval before constraint validation.Experiments on three benchmark datasets show that CoR consistently outperforms strong baselines in both F1 score and KG-grounded Rate.