Fine-Tuning or Retrieval? Comparing Knowledge Injection in LLMs

Oded Ovadia, Menachem Brief, Moshik Mishaeli, Oren Elisha


Abstract
Large language models (LLMs) encapsulate a vast amount of factual information within their pre-trained weights, as evidenced by their ability to answer diverse questions across different domains. However, this knowledge is inherently limited, relying heavily on the characteristics of the training data. Consequently, using external datasets to incorporate new information or refine the capabilities of LLMs on previously seen information poses a significant challenge. In this study, we compare two common approaches: unsupervised fine-tuning and retrieval-augmented generation (RAG). We evaluate both approaches on a variety of knowledge-intensive tasks across different topics. Our findings reveal that while unsupervised fine-tuning offers some improvement, RAG consistently outperforms it, both for existing knowledge encountered during training and entirely new knowledge. Moreover, we find that LLMs struggle to learn new factual information through unsupervised fine-tuning, and that exposing them to numerous variations of the same fact during training could alleviate this problem.
Anthology ID:
2024.emnlp-main.15
Volume:
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
237–250
Language:
URL:
https://aclanthology.org/2024.emnlp-main.15
DOI:
10.18653/v1/2024.emnlp-main.15
Bibkey:
Cite (ACL):
Oded Ovadia, Menachem Brief, Moshik Mishaeli, and Oren Elisha. 2024. Fine-Tuning or Retrieval? Comparing Knowledge Injection in LLMs. In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 237–250, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Fine-Tuning or Retrieval? Comparing Knowledge Injection in LLMs (Ovadia et al., EMNLP 2024)
Copy Citation:
PDF:
https://aclanthology.org/2024.emnlp-main.15.pdf