Retention analysis of edited knowledge after fine-tuning

TL;DR

This paper investigates how fine-tuning affects previously edited knowledge in large language models, revealing increased susceptibility to forgetting and proposing methods to improve knowledge retention.

Contribution

It systematically analyzes the interaction between fine-tuning and model editing techniques, highlighting limitations and proposing strategies for more robust knowledge editing.

Findings

Edited knowledge is more prone to forgetting during fine-tuning than intrinsic knowledge.

Augmenting edits with paraphrases improves retention.

Freezing layers related to edited content enhances knowledge preservation.

Abstract

Large language models (LLMs) store vast amounts of knowledge, which often requires updates to correct factual errors, incorporate newly acquired information, or adapt model behavior. Model editing methods have emerged as efficient solutions for such updates, offering localized and precise knowledge modification at significantly lower computational cost than continual training. In parallel, LLMs are frequently fine-tuned for a wide range of downstream tasks. However, the effect of fine-tuning on previously edited knowledge remains poorly understood. In this work, we systematically investigate how different fine-tuning objectives interact with various model editing techniques. Our findings show that edited knowledge is substantially more susceptible to forgetting during fine-tuning than intrinsic knowledge acquired through pre-training. This analysis highlights a key limitation of current editing approaches and suggests that evaluating edit robustness under downstream fine-tuning is critical for their practical deployment. We further find that knowledge retention can be significantly improved by either augmenting edit knowledge with paraphrases or by freezing layers associated with edited content in fine-tuning stage, offering insight for developing more robust editing algorithms.