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arXiv 2405.12579cs.CL

挖掘可解释性与泛化性:基于自我指令的事实核查

Mining the Explainability and Generalization: Fact Verification Based on Self-Instruction

College of Computer Science and Electronic Engineering, Hunan University(湖南大学计算机与通信电子学院)

Guangyao Lu, Yulin Liu

AI总结:

本文提出一种基于自我指令的微调方法,结合数据增强和改进的DPO,在保持可解释性的同时提升事实核查的准确性和泛化性,并在FEVEROUS和HOVER数据集上验证了其有效性。

摘要:

基于商业大语言模型(LLM)的事实核查已成为主流。尽管这些方法具有较高的可解释性,但在准确性上不如传统的微调方法,且数据安全也是一个重要问题。在本文中,我们提出了一种基于自我指令的微调方法用于事实核查,以平衡准确性和可解释性。我们的方法包括数据增强和改进的DPO(直接偏好优化)微调。前者首先指导模型基于声明-证据对和标签生成正面和负面的解释,然后根据我们定制的难度标准对数据集进行采样。后者采用我们提出的改进DPO,使用生成的样本对模型进行微调。我们微调了最小规模的LLaMA-7B模型,并在具有挑战性的事实核查数据集FEVEROUS和HOVER上进行了评估,使用了四种微调方法和三种少样本学习方法进行比较。实验表明,我们的方法不仅保持了与传统微调方法相当甚至超越的准确性,而且生成了流畅的解释文本。此外,它还表现出较高的泛化性能。我们的方法是首个将自监督学习用于事实核查的方法,并创新性地在微调大语言模型时结合了对比学习和改进的DPO,如实验所示。

英文摘要:

Fact-checking based on commercial LLMs has become mainstream. Although these methods offer high explainability, it falls short in accuracy compared to traditional fine-tuning approaches, and data security is also a significant concern. In this paper, we propose a self-instruction based fine-tuning approach for fact-checking that balances accuracy and explainability. Our method consists of Data Augmentation and Improved DPO fine-tuning. The former starts by instructing the model to generate both positive and negative explanations based on claim-evidence pairs and labels, then sampling the dataset according to our customized difficulty standards. The latter employs our proposed improved DPO to fine-tune the model using the generated samples. We fine-tune the smallest-scale LLaMA-7B model and evaluate it on the challenging fact-checking datasets FEVEROUS and HOVER, utilizing four fine-tuning methods and three few-shot learning methods for comparison. The experiments demonstrate that our approach not only retains accuracy comparable to, or even surpassing, traditional fine-tuning methods, but also generates fluent explanation text. Moreover, it also exhibit high generalization performance. Our method is the first to leverage self-supervised learning for fact-checking and innovatively combines contrastive learning and improved DPO in fine-tuning LLMs, as shown in the experiments.

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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