Scaling Laws for Forgetting When Fine-Tuning Large Language Models

Fuente: arXiv
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Main Author: Kalajdzievski, Damjan
Format: Preprint
Published: 2024
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author Kalajdzievski, Damjan
author_facet Kalajdzievski, Damjan
contents We study and quantify the problem of forgetting when fine-tuning pre-trained large language models (LLMs) on a downstream task. We find that parameter-efficient fine-tuning (PEFT) strategies, such as Low-Rank Adapters (LoRA), still suffer from catastrophic forgetting. In particular, we identify a strong inverse linear relationship between the fine-tuning performance and the amount of forgetting when fine-tuning LLMs with LoRA. We further obtain precise scaling laws that show forgetting increases as a shifted power law in the number of parameters fine-tuned and the number of update steps. We also examine the impact of forgetting on knowledge, reasoning, and the safety guardrails trained into Llama 2 7B chat. Our study suggests that forgetting cannot be avoided through early stopping or by varying the number of parameters fine-tuned. We believe this opens up an important safety-critical direction for future research to evaluate and develop fine-tuning schemes which mitigate forgetting
format Preprint
id arxiv_https___arxiv_org_abs_2401_05605
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Scaling Laws for Forgetting When Fine-Tuning Large Language Models
Kalajdzievski, Damjan
Computation and Language
Machine Learning
I.2.7
We study and quantify the problem of forgetting when fine-tuning pre-trained large language models (LLMs) on a downstream task. We find that parameter-efficient fine-tuning (PEFT) strategies, such as Low-Rank Adapters (LoRA), still suffer from catastrophic forgetting. In particular, we identify a strong inverse linear relationship between the fine-tuning performance and the amount of forgetting when fine-tuning LLMs with LoRA. We further obtain precise scaling laws that show forgetting increases as a shifted power law in the number of parameters fine-tuned and the number of update steps. We also examine the impact of forgetting on knowledge, reasoning, and the safety guardrails trained into Llama 2 7B chat. Our study suggests that forgetting cannot be avoided through early stopping or by varying the number of parameters fine-tuned. We believe this opens up an important safety-critical direction for future research to evaluate and develop fine-tuning schemes which mitigate forgetting
title Scaling Laws for Forgetting When Fine-Tuning Large Language Models
topic Computation and Language
Machine Learning
I.2.7
url https://arxiv.org/abs/2401.05605