EPERM: An Evidence Path Enhanced Reasoning Model for Knowledge Graph Question and Answering
This work addresses the issue of hallucinations and knowledge gaps in LLMs for domain-specific KGQA tasks, offering an incremental improvement over prior retrieval-based methods.
The paper tackles the problem of improving large language models' reasoning in knowledge graph question answering by addressing the neglect of different knowledge types in existing methods, proposing EPERM, a three-stage framework that retrieves, filters, and weights evidence paths, achieving superior performance on benchmark datasets.
Due to the remarkable reasoning ability, Large language models (LLMs) have demonstrated impressive performance in knowledge graph question answering (KGQA) tasks, which find answers to natural language questions over knowledge graphs (KGs). To alleviate the hallucinations and lack of knowledge issues of LLMs, existing methods often retrieve the question-related information from KGs to enrich the input context. However, most methods focus on retrieving the relevant information while ignoring the importance of different types of knowledge in reasoning, which degrades their performance. To this end, this paper reformulates the KGQA problem as a graphical model and proposes a three-stage framework named the Evidence Path Enhanced Reasoning Model (EPERM) for KGQA. In the first stage, EPERM uses the fine-tuned LLM to retrieve a subgraph related to the question from the original knowledge graph. In the second stage, EPERM filters out the evidence paths that faithfully support the reasoning of the questions, and score their importance in reasoning. Finally, EPERM uses the weighted evidence paths to reason the final answer. Since considering the importance of different structural information in KGs for reasoning, EPERM can improve the reasoning ability of LLMs in KGQA tasks. Extensive experiments on benchmark datasets demonstrate that EPERM achieves superior performances in KGQA tasks.