Small Models are Valuable Plug-ins for Large Language Models
Canwen Xu, Yichong Xu, Shuohang Wang, Yang Liu, Chenguang Zhu, Julian McAuley
TL;DR
This work introduces Super In-Context Learning (SuperICL), a framework that pairs a black-box LLM with locally fine-tuned plug-in models to improve supervised task performance while mitigating ICL instability. By fine-tuning a small plug-in, constructing confidence-informed contexts, and letting the LLM override plug-in predictions when appropriate, SuperICL achieves superior results on GLUE and competitive cross-lingual gains on XNLI. The approach enhances interpretability through explanations and shows robustness improvements, albeit with sensitivity to plug-in quality and adversarial vulnerabilities. The study demonstrates a practical paradigm for leveraging both cloud-based LLMs and local models to advance supervised learning under context limits and resource constraints.
Abstract
Large language models (LLMs) such as GPT-3 and GPT-4 are powerful but their weights are often publicly unavailable and their immense sizes make the models difficult to be tuned with common hardware. As a result, effectively tuning these models with large-scale supervised data can be challenging. As an alternative, In-Context Learning (ICL) can only use a small number of supervised examples due to context length limits. In this paper, we propose Super In-Context Learning (SuperICL) which allows black-box LLMs to work with locally fine-tuned smaller models, resulting in superior performance on supervised tasks. Our experiments demonstrate that SuperICL can improve performance beyond state-of-the-art fine-tuned models while addressing the instability problem of in-context learning. Furthermore, SuperICL can enhance the capabilities of smaller models, such as multilinguality and interpretability.
