arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2602.22787cs.CLcs.AI
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探测大型语言模型中的知识归因

Probing for Knowledge Attribution in Large Language Models

KPMG NL(KPMG荷兰分公司);University of Amsterdam(阿姆斯特丹大学)

Ivo Brink, Alexander Boer, Dennis Ulmer

AI总结:

本文通过线性探针从隐藏表示中分类大型语言模型输出的主导知识来源(记忆或上下文),并引入自监督流水线AttriWiki生成训练数据,在多个模型和数据集上达到高F1分数。

摘要:

大型语言模型(LLM)的幻觉,即流畅但事实不正确的生成,分为两类:忠实性违反,即模型误用提供的上下文;以及事实性违反,即答案反映内部知识中的错误。适当的缓解取决于知道哪个来源驱动每个答案。我们研究贡献性归因,即对每个输出背后的主导知识来源进行分类,并表明在隐藏表示上训练的简单线性探针可以可靠地识别它。我们引入了AttriWiki,一个自监督流水线,通过提示模型从记忆中回忆被隐藏的实体或从上下文中读取它们,而不依赖知识冲突,自动生成标记的训练数据。在AttriWiki上训练的探针在Llama-3.1-8B、Mistral-7B和Qwen-7B上达到高达0.96的Macro-$F_1$,迁移到SQuAD和WebQuestions时达到0.94-0.99的Macro-$F_1$,并零样本泛化到Tighidet等人(2024)的基准,在冲突设置上无需重新训练即优于他们的探针。此外,归因不匹配会使错误率提高高达70%,尽管正确的归因并不能保证正确的答案,这表明需要更广泛的检测框架。

英文摘要:

Large language model (LLM) hallucinations, meaning fluent but factually incorrect generations, fall into two types: faithfulness violations, where the model misuses provided context, and factuality violations, where answers reflect errors in internal knowledge. Proper mitigation depends on knowing which source drives each answer. We study contributive attribution, i.e. the classification of the dominant knowledge source behind each output, and show that a simple linear probe trained on hidden representations can reliably identify it. We introduce AttriWiki, a self-supervised pipeline that automatically generates labelled training data by prompting models to recall withheld entities from memory or read them from context without relying on knowledge conflicts. Probes trained on AttriWiki achieve up to 0.96 Macro-$F_1$ on Llama-3.1-8B, Mistral-7B, and Qwen-7B, transfer to SQuAD and WebQuestions with 0.94-0.99 Macro-$F_1$, and generalise zero-shot to Tighidet et al. (2024)'s benchmark, outperforming their probe on conflicting settings without retraining. Furthermore, attribution mismatches raise error rates by up to 70%, though correct attribution does not guarantee correct answers, pointing to the need for broader detection frameworks.

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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