Augmentation-Adapted Retriever Improves Generalization of Language Models as Generic Plug-In

Zichun Yu, Chenyan Xiong, Shi Yu, Zhiyuan Liu


Abstract
Retrieval augmentation can aid language models (LMs) in knowledge-intensive tasks by supplying them with external information. Prior works on retrieval augmentation usually jointly fine-tune the retriever and the LM, making them closely coupled. In this paper, we explore the scheme of generic retrieval plug-in: the retriever is to assist target LMs that may not be known beforehand or are unable to be fine-tuned together. To retrieve useful documents for unseen target LMs, we propose augmentation-adapted retriever (AAR), which learns LM’s preferences obtained from a known source LM. Experiments on the MMLU and PopQA datasets demonstrate that our AAR trained with a small source LM is able to significantly improve the zero-shot generalization of larger target LMs ranging from 250M Flan-T5 to 175B InstructGPT. Further analysis indicates that the preferences of different LMs overlap, enabling AAR trained with a single source LM to serve as a generic plug-in for various target LMs. Our code is open-sourced at https://github.com/OpenMatch/Augmentation-Adapted-Retriever.
Anthology ID:
2023.acl-long.136
Volume:
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2023
Address:
Toronto, Canada
Editors:
Anna Rogers, Jordan Boyd-Graber, Naoaki Okazaki
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2421–2436
Language:
URL:
https://aclanthology.org/2023.acl-long.136
DOI:
10.18653/v1/2023.acl-long.136
Bibkey:
Cite (ACL):
Zichun Yu, Chenyan Xiong, Shi Yu, and Zhiyuan Liu. 2023. Augmentation-Adapted Retriever Improves Generalization of Language Models as Generic Plug-In. In Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 2421–2436, Toronto, Canada. Association for Computational Linguistics.
Cite (Informal):
Augmentation-Adapted Retriever Improves Generalization of Language Models as Generic Plug-In (Yu et al., ACL 2023)
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