Small Models, Big Insights: Leveraging Slim Proxy Models To Decide When and What to Retrieve for LLMs
(2402.12052)Abstract
The integration of LLMs and search engines represents a significant evolution in knowledge acquisition methodologies. However, determining the knowledge that an LLM already possesses and the knowledge that requires the help of a search engine remains an unresolved issue. Most existing methods solve this problem through the results of preliminary answers or reasoning done by the LLM itself, but this incurs excessively high computational costs. This paper introduces a novel collaborative approach, namely SlimPLM, that detects missing knowledge in LLMs with a slim proxy model, to enhance the LLM's knowledge acquisition process. We employ a proxy model which has far fewer parameters, and take its answers as heuristic answers. Heuristic answers are then utilized to predict the knowledge required to answer the user question, as well as the known and unknown knowledge within the LLM. We only conduct retrieval for the missing knowledge in questions that the LLM does not know. Extensive experimental results on five datasets with two LLMs demonstrate a notable improvement in the end-to-end performance of LLMs in question-answering tasks, achieving or surpassing current state-of-the-art models with lower LLM inference costs.
Overview
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Introduces SlimPLM, a method enhancing LLMs through efficient knowledge retrieval via a smaller proxy model.
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Addresses challenges of unnecessary retrieval and computational demands in LLMs, improving question-answering performance.
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Demonstrates SlimPLM's ability to make informed decisions about when and what external knowledge to retrieve, significantly reducing inference costs.
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Presents a potential for future research in refining proxy models and expanding SlimPLM's adaptability across various domains.
Leveraging Slim Proxy Models for Efficient Knowledge Retrieval in LLMs
Introduction to SlimPLM
In recent research, a novel method named SlimPLM (Slim Proxy Language Model) is introduced for enhancing the functionality of LLMs through efficient and targeted knowledge retrieval. SlimPLM proposes a unique approach by incorporating a smaller proxy model to decide when and what external knowledge should be retrieved to answer a user's question. This alleviates the need for unnecessary retrieval, thus reducing computational costs while maintaining or even surpassing the state-of-the-art performance in question-answering tasks across various datasets.
The Challenge with Existing Methods
The integration of LLMs with retrieval systems has been a significant advancement in improving the quality of generated text by LLMs. However, determining the necessity and timing for retrieval poses challenges, including increased computational demands and potential degradation in performance due to irrelevant information retrieval. SlimPLM aims to address these challenges by using a proxy model, thereby offering an efficient solution.
SlimPLM Methodology
- Proxy Model Utilization: The core of SlimPLM is its leveraging of a smaller model as a heuristic tool. This "proxy model" processes user questions to predict the LLM's existing knowledge and identifies gaps that require external retrieval.
- Retrieval Necessity and Query Rewriting: SlimPLM enhances decision-making for retrieval by assessing the heuristic answer's quality produced by the proxy model. A low-quality heuristic answer triggers a retrieval process, where the proxy's output also aids in generating refined queries, ensuring relevant knowledge is sought.
- Experimental Validation: Conducted across five question-answering datasets, SlimPLM demonstrably enhanced LLMs' performance in various natural language processing tasks. Notably, it maintained or improved upon current models' achievements with significantly lower inference costs.
Contributions and Implications
SlimPLM's introduction marks a significant step toward optimizing knowledge retrieval in LLMs, contributing to:
- Efficient determination of retrieval necessity via a smaller proxy model, minimizing unwarranted external searches.
- Enhanced relevance in retrieval through heuristic answer-based refined query generation.
- Notable performance improvements in end-to-end question-answering tasks without increasing computational overhead.
The practical implications of this approach are profound, especially in environments where computational resources are limited, and the need for precise, efficient retrieval is paramount. The ability of SlimPLM to judiciously decide when to engage in retrieval and what information to seek can lead to more sustainable and cost-effective deployments of advanced LLMs.
Future Directions
Looking forward, the application of SlimPLM opens new avenues for research, particularly in refining the proxy model's accuracy and expanding the method's adaptability across various domains. Furthermore, simplifying the current three-model pipeline into a more integrated system could further enhance efficiency and applicability. The exploration of proxy models in different sizes and configurations also presents an exciting area for further investigation, potentially leading to more tailored and domain-specific solutions.
Conclusion
SlimPLM's innovative approach to utilizing slim proxy models for effective retrieval represents a significant stride in the ongoing evolution of LLMs. By intelligently determining the need for external knowledge retrieval, SlimPLM not only optimizes the performance of LLMs in rendering accurate answers but also significantly reduces computational demands. As such, SlimPLM establishes a promising foundation for future endeavors aiming to harmonize efficiency with performance in the realm of generative AI and LLMs.
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