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arXiv 2404.01430cs.CLcs.AIcs.LG
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面向位置感知的参数高效微调方法以减少大语言模型中的位置偏差

Position-Aware Parameter Efficient Fine-Tuning Approach for Reducing Positional Bias in LLMs

Amazon(亚马逊);Emory University(埃默里大学)

Zheng Zhang, Fan Yang, Ziyan Jiang, Zheng Chen, Zhengyang Zhao, Chengyuan Ma, Liang Zhao, Yang Liu

AI总结:

本文针对大语言模型处理长上下文时的位置偏差问题,提出位置感知的参数高效微调方法PAPEFT,通过数据增强和参数高效适配器促进均匀注意力分布,实验证明其能有效减少位置偏差并提升外部知识检索任务性能。

摘要:

大语言模型(LLMs)的最新进展增强了它们处理长输入上下文的能力。这一发展对于涉及从外部数据存储中检索知识的任务尤为关键,因为这类任务可能产生长输入。然而,近期研究表明LLMs存在位置偏差,即模型性能会因有用信息在输入序列中的位置不同而变化。在本研究中,我们进行了大量实验以探究位置偏差的根本原因。我们的研究结果表明,导致LLM位置偏差的主要因素源于不同模型固有的位置偏好。我们证明,仅采用基于提示的方法不足以克服这些位置偏好。为了解决预训练LLM的这一位置偏差问题,我们开发了一种位置感知的参数高效微调(PAPEFT)方法,该方法由一种数据增强技术和一种参数高效适配器组成,可增强输入上下文中的均匀注意力分布。我们的实验表明,所提出的方法能够有效减少位置偏差,提高LLMs在处理需要外部检索知识的各种任务中长上下文序列的有效性。

英文摘要:

Recent advances in large language models (LLMs) have enhanced their ability to process long input contexts. This development is particularly crucial for tasks that involve retrieving knowledge from an external datastore, which can result in long inputs. However, recent studies show a positional bias in LLMs, demonstrating varying performance depending on the location of useful information within the input sequence. In this study, we conduct extensive experiments to investigate the root causes of positional bias. Our findings indicate that the primary contributor to LLM positional bias stems from the inherent positional preferences of different models. We demonstrate that merely employing prompt-based solutions is inadequate for overcoming the positional preferences. To address this positional bias issue of a pre-trained LLM, we developed a Position-Aware Parameter Efficient Fine-Tuning (PAPEFT) approach which is composed of a data augmentation technique and a parameter efficient adapter, enhancing a uniform attention distribution across the input context. Our experiments demonstrate that the proposed approach effectively reduces positional bias, improving LLMs' effectiveness in handling long context sequences for various tasks that require externally retrieved knowledge.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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