By providing external information to large language models (LLMs), tool augmentation (including retrieval augmentation) has emerged as a promising solution for addressing the limitations of LLMs' static parametric memory. However, how receptive are LLMs to such external evidence, especially when the evidence conflicts with their parametric memory? We present the first comprehensive and controlled investigation into the behavior of LLMs when encountering knowledge conflicts. We propose a systematic framework to elicit high-quality parametric memory from LLMs and construct the corresponding counter-memory, which enables us to conduct a series of controlled experiments. Our investigation reveals seemingly contradicting behaviors of LLMs. On the one hand, different from prior wisdom, we find that LLMs can be highly receptive to external evidence even when that conflicts with their parametric memory, given that the external evidence is coherent and convincing. On the other hand, LLMs also demonstrate a strong confirmation bias when the external evidence contains some information that is consistent with their parametric memory, despite being presented with conflicting evidence at the same time. These results pose important implications that are worth careful consideration for the further development and deployment of tool- and retrieval-augmented LLMs.

本文提出了一种系统性方法，通过对LLMs的参数化记忆进行质量控制来构建相应的反记忆，并借此进行了一系列受控实验，研究了LLMs在遇到知识冲突时的行为，发现LLMs在保持一致性和可信性的情况下，即使与其参数化记忆冲突，也可以高度接受外部证据，但在提供与其参数化记忆一致的信息时，它们也表现出强烈的确认偏差。这些结果对工具和检索增强LLMs的进一步开发和部署具有重要意义。

大型语言模型在知识冲突中的行为：自适应变色龙或顽固树懒