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arXiv 2405.01525cs.CLcs.AI

FLAME:面向大语言模型的事实性感知对齐

FLAME: Factuality-Aware Alignment for Large Language Models

University of Waterloo(滑铁卢大学);Carnegie Mellon University(卡内基梅隆大学);Meta AI

Sheng-Chieh Lin, Luyu Gao, Barlas Oguz, Wenhan Xiong, Jimmy Lin, Wen-tau Yih, Xilun Chen

AI总结:

本文提出FLAME事实性感知对齐方法,通过改进SFT和RL两个阶段抑制大语言模型幻觉,在保持指令遵循能力的同时提升回复的事实准确性。

摘要:

对齐是微调预训练大语言模型(LLMs)以遵循自然语言指令并作为有用AI助手的标准流程。然而我们观察到,传统对齐过程未能提升LLMs的事实准确性,并且常常导致生成更多虚假事实(即幻觉)。本文研究如何使LLM对齐过程更具事实性,首先识别在对齐的两个步骤——监督微调(SFT)和强化学习(RL)——中导致幻觉的因素。特别是,我们发现用新知识或不熟悉文本训练LLM会助长幻觉。这使得SFT的事实性较差,因为它训练所用的人工标注数据对LLM而言可能是新颖的。此外,标准RL中使用的奖励函数也会助长幻觉,因为它引导LLM在多样化指令集上提供更有帮助的回复,往往偏好更长、更详细的回复。基于这些观察,我们提出事实性感知对齐,由事实性感知SFT和通过直接偏好优化实现的事实性感知RL组成。实验表明,我们提出的事实性感知对齐能引导LLM输出更具事实性的回复,同时保持指令遵循能力。

英文摘要:

Alignment is a standard procedure to fine-tune pre-trained large language models (LLMs) to follow natural language instructions and serve as helpful AI assistants. We have observed, however, that the conventional alignment process fails to enhance the factual accuracy of LLMs, and often leads to the generation of more false facts (i.e. hallucination). In this paper, we study how to make the LLM alignment process more factual, by first identifying factors that lead to hallucination in both alignment steps:\ supervised fine-tuning (SFT) and reinforcement learning (RL). In particular, we find that training the LLM on new knowledge or unfamiliar texts can encourage hallucination. This makes SFT less factual as it trains on human labeled data that may be novel to the LLM. Furthermore, reward functions used in standard RL can also encourage hallucination, because it guides the LLM to provide more helpful responses on a diverse set of instructions, often preferring longer and more detailed responses. Based on these observations, we propose factuality-aware alignment, comprised of factuality-aware SFT and factuality-aware RL through direct preference optimization. Experiments show that our proposed factuality-aware alignment guides LLMs to output more factual responses while maintaining instruction-following capability.

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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