Retrieval-Enhanced Knowledge Editing for Multi-Hop Question Answering in Language Models
(2403.19631)Abstract
LLMs have shown proficiency in question-answering tasks but often struggle to integrate real-time knowledge updates, leading to potentially outdated or inaccurate responses. This problem becomes even more challenging when dealing with multi-hop questions since they require LLMs to update and integrate multiple knowledge pieces relevant to the questions. To tackle the problem, we propose the Retrieval-Augmented model Editing (RAE) framework tailored for multi-hop question answering. RAE first retrieves edited facts and then refines the language model through in-context learning. Specifically, our retrieval approach, based on mutual information maximization, leverages the reasoning abilities of LLMs to identify chain facts that na\"ive similarity-based searches might miss. Additionally, our framework incorporates a pruning strategy to eliminate redundant information from the retrieved facts, which enhances the editing accuracy and mitigates the hallucination problem. Our framework is supported by theoretical justification for its fact retrieval efficacy. Finally, comprehensive evaluation across various LLMs validates RAE's ability in providing accurate answers with updated knowledge.
Overview
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The paper introduces a novel Retrieval-Augmented model Editing (RAE) framework for enhancing multi-hop question answering in LLMs, tailored to dynamically integrate real-time knowledge updates.
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RAE incorporates novel retrieval techniques using mutual information maximization and a knowledge pruning method to refine the model’s responses, ensuring higher relevance and accuracy.
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The framework is grounded in information theory, aiming to maximize mutual information between the question and retrieved facts to align closely with the necessary knowledge for accurate answers.
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Empirical evaluations demonstrate RAE’s superiority in handling complex multi-hop questions across various language models, outperforming existing state-of-the-art methods.
Enhancing Multi-Hop Question Answering in LLMs with Retrieval-Augmented Model Editing
Introduction to Retrieval-Augmented Model Editing (RAE)
The paper introduces a novel Retrieval-Augmented model Editing (RAE) framework designed specifically for multi-hop question answering using LLMs. Recognizing the challenge in incorporating real-time knowledge updates, especially in a multi-hop context, RAE leverages a strategy that first retrieves edited facts and then refines the model's response through in-context learning. The framework is distinct in its use of mutual information maximization for retrieval, effectively enhancing the model's ability to identify and integrate relevant knowledge pieces.
Key Contributions
- Novel Retrieval Approach: Utilization of mutual information maximization to retrieve the most relevant multi-hop edited facts, effectively using the reasoning capabilities of LLMs.
- Pruning Strategy: Introduction of a knowledge pruning method to eliminate redundant information post-retrieval, ensuring that only pertinent information influences the model’s output.
- Theoretical Justification: Provision of a theoretical foundation validating the approach for fact retrieval efficacy.
- Extensive Validation: Empirical demonstrations of RAE's effectiveness across multiple language models, substantiating its superiority in handling multi-hop questions over several state-of-the-art methods.
Methodological Framework
The RAE framework consists of two main components:
- Edited Facts Retrieval: By maximizing mutual information, the method focuses on retrieving a knowledge graph subset most informative about the query. This process is dependent on the effective estimation of conditional probabilities using the next-word prediction capability of LLMs.
- Knowledge Pruning: Upon retrieving a broad set of potentially relevant facts, RAE prunes this set based on the editing uncertainty, which is quantified by the output entropy of the LLM when presented with each subset of facts.
Theoretical Underpinnings
RAE's effectiveness stems from its grounding in information theory, particularly the principles surrounding mutual information. By attempting to maximize the mutual information between the question and the retrieved facts, RAE ensures that the edits align closely with the knowledge required to answer the question accurately. This approach is theoretically justified to align the retrieval process with the end goal of accurate and relevant model editing.
Empirical Evaluation
The RAE framework was subjected to rigorous testing across various datasets and models, demonstrating its adaptability and effectiveness. It consistently outperformed other model editing techniques, particularly in scenarios involving complex multi-hop question answering. These results highlight its practical utility and the potential for broader applications in real-world scenarios where LLMs need to dynamically integrate updated knowledge.
Future Directions
- Scalability and Efficiency: Improving the efficiency of the retrieval process, possibly by enhancing the mutual information estimation techniques or integrating more computationally efficient models.
- Broader Applicability: Extending the framework to other forms of dynamic knowledge integration such as real-time information updates from continuous data streams.
- Domain-Specific Adaptations: Customizing the RAE framework for specific domains like medical or legal question answering, where accuracy and up-to-date information are critical.
The RAE framework marks a significant step forward in the realm of knowledge-intensive applications for LLMs, particularly enhancing their capability to handle multi-hop question answering through effective retrieval and editing of relevant facts. Its success opens avenues for more sophisticated and context-aware AI systems, capable of adapting to evolving information landscapes.
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