RUIE: Retrieval-based Unified Information Extraction using Large Language Model
Xincheng Liao, Junwen Duan, Yixi Huang, Jianxin Wang
TL;DR
RUIE presents a retrieval-based UIE framework that enables efficient out-of-distribution generalization for NER, RE, and EE by coupling a trainable bi-encoder retriever with LLM-driven in-context learning. A novel demonstration selection mechanism combines LLM preferences with a keyword-enhanced reward to guide multi-task example retrieval, while a contrastive loss and knowledge distillation align the retriever with the reward model. Empirical results on 31 held-in and 8 held-out datasets show substantial improvements over instruction-tuning and other retrievers, with average F1-score gains of 19.22 and 3.22, respectively, across tasks. The approach reduces computation by avoiding full LLM fine-tuning and offers flexibility to work with various LLMs, making UIE more scalable and practical for real-world deployments. Limitations include sentence-length constraints, a gap to SFT methods on seen tasks, and English-only evaluation, suggesting directions for future multilingual and long-document UIE extensions.
Abstract
Unified information extraction (UIE) aims to extract diverse structured information from unstructured text. While large language models (LLMs) have shown promise for UIE, they require significant computational resources and often struggle to generalize to unseen tasks. We propose RUIE (Retrieval-based Unified Information Extraction), a framework that leverages in-context learning for efficient task generalization. RUIE introduces a novel demonstration selection mechanism combining LLM preferences with a keyword-enhanced reward model, and employs a bi-encoder retriever trained through contrastive learning and knowledge distillation. As the first trainable retrieval framework for UIE, RUIE serves as a universal plugin for various LLMs. Experimental results on eight held-out datasets demonstrate RUIE's effectiveness, with average F1-score improvements of 19.22 and 3.22 compared to instruction-tuning methods and other retrievers, respectively.
