arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2502.10596cs.CLcs.AIcs.LG
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后训练用于RAG的LLM?基于自生成示范进行训练

Post-training an LLM for RAG? Train on Self-Generated Demonstrations

University of Southern California(南加州大学);Meta, Inc.(元公司)

Matthew Finlayson, Ilia Kulikov, Daniel M. Bikel, Barlas Oguz, Xilun Chen, Aasish Pappu

AI总结:

提出基于自生成示范训练RAG-LLM的方案,通过避免分布外数据训练并将检索整合进响应,在提升问答性能与实现弃权(不执行)的同时防止非RAG场景下的模型退化。

摘要:

大型语言模型(LLMs)通常难以应对知识密集型NLP任务,例如回答“谁赢得了最近的世界杯?”,因为它们在训练期间学到的知识可能不足或已过时。基于检索文档来约束生成——一种被称为检索增强生成(RAG)的技术——通过允许模型利用上下文信息来缓解这些缺陷。从业者可以通过在检索增强指令上进行微调来提高LLM的RAG性能,但必须注意这可能导致幻觉等不良模型行为。我们将这种退化归因于训练数据可能对模型而言属于分布外,且可能存在质量问题,例如检索内容与目标响应之间的错位(因为检索内容通常是事后添加的)。我们提出了一种使用自生成示范来训练启用RAG的LLM的方案,从而避免在分布外文本上训练,并将检索内容整合到LLM的响应中。我们在知识密集型问答(QA)任务上评估了我们的方法,并表明我们的方法教会了LLM正确处理上下文检索内容,并对其可能答错的问题弃权(不执行)。与传统的RA-IT方法相比,我们的方法在非RAG设置下防止了模型退化,同时展现出优越的QA性能。

英文摘要:

Large language models (LLMs) often struggle with knowledge intensive NLP tasks, such as answering "Who won the latest World Cup?" because the knowledge they learn during training may be insufficient or outdated. Conditioning generation on retrieved documents -- a technique known as retrieval augmented generation (RAG) -- mitigates these shortcomings by allowing the model to leverage in-context information. Practitioners can improve LLM RAG performance by fine-tuning on retrieval-augmented instructions, but must beware that this can cause undesirable model behaviors like hallucinations. We attribute this degradation to the fact that the training data is likely to be out-of-distribution for the model and may suffer from quality issues, such as misalignment between retrievals and target responses (since retrievals are frequently added post-hoc). We propose a recipe for training RAG-enabled LLMs using self-generated demonstrations, thereby avoiding training on out-of-distribution text and integrating retrievals into the LLM responses. We evaluate our method on knowledge intensive question answering (QA) tasks and show that our method teaches LLMs to properly handle in-context retrievals and abstain from questions it will likely get wrong. Compared to conventional RA-IT methods, our method prevents model degradation in non-RAG settings while exhibiting superior QA performance.

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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