KGFR: A Foundation Retriever for Generalized Knowledge Graph Question Answering
Yuanning Cui, Zequn Sun, Wei Hu, Zhangjie Fu
TL;DR
The paper addresses knowledge-grounded question answering by combining large language models with a structured, scalable KG retriever. It introduces KGFR, a zero-shot, non-finetuned retriever that uses LLM-generated unified relation descriptions and question-conditioned propagation, aided by Asymmetric Progressive Propagation to scale to million-scale graphs. A controller–retriever loop enables iterative reasoning with multi-level retrieval (node, edge, path) and a reflection mechanism, enabling robust generalization to unseen KGs and datasets. Experiments across seven KGQA benchmarks show strong accuracy, scalability, and transferability, with ablation studies validating the contribution of each component and evidence that the approach reduces reliance on LLM finetuning while maintaining interpretability and efficiency.
Abstract
Large language models (LLMs) excel at reasoning but struggle with knowledge-intensive questions due to limited context and parametric knowledge. However, existing methods that rely on finetuned LLMs or GNN retrievers are limited by dataset-specific tuning and scalability on large or unseen graphs. We propose the LLM-KGFR collaborative framework, where an LLM works with a structured retriever, the Knowledge Graph Foundation Retriever (KGFR). KGFR encodes relations using LLM-generated descriptions and initializes entities based on their roles in the question, enabling zero-shot generalization to unseen KGs. To handle large graphs efficiently, it employs Asymmetric Progressive Propagation (APP)- a stepwise expansion that selectively limits high-degree nodes while retaining informative paths. Through node-, edge-, and path-level interfaces, the LLM iteratively requests candidate answers, supporting facts, and reasoning paths, forming a controllable reasoning loop. Experiments demonstrate that LLM-KGFR achieves strong performance while maintaining scalability and generalization, providing a practical solution for KG-augmented reasoning.
