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arXiv 2408.02152cs.IRcs.AIcs.CLcs.LG

基于少样本索引的生成检索

Generative Retrieval with Few-shot Indexing

Leiden University(莱顿大学);The University of Edinburgh(爱丁堡大学);University of Amsterdam(阿姆斯特丹大学)

Arian Askari, Chuan Meng, Mohammad Aliannejadi, Zhaochun Ren, Evangelos Kanoulas, Suzan Verberne

AI总结:

本文提出了一种无需训练的少样本索引生成检索框架,通过提示LLM生成文档标识符来提升检索性能。

摘要:

现有的生成检索(GR)方法依赖于基于训练的索引,该方法通过微调模型来记忆查询与相关文档标识符(docids)之间的关联。基于训练的索引存在训练成本高、未能充分利用大语言模型(LLMs)中的预训练知识以及对动态文档语料库适应性差的问题。为了解决这些问题,我们提出了一种基于少样本索引的生成检索框架(Few-Shot GR)。该框架包含一个无需任何训练的少样本索引过程,其中我们提示LLM生成语料库中所有文档的docids,最终为整个语料库创建一个docid库。在检索过程中,我们将查询输入相同的LLM,并限制其生成一个在索引过程中创建的docid库中的docid,然后将生成的docid映射回其对应的文档。此外,我们还设计了具有一对一映射的少样本索引以进一步增强Few-Shot GR。实验表明,Few-Shot GR在需要重训练的最先进GR方法上表现更优。

英文摘要:

Existing generative retrieval (GR) methods rely on training-based indexing, which fine-tunes a model to memorise associations between queries and the document identifiers (docids) of relevant documents. Training-based indexing suffers from high training costs, under-utilisation of pre-trained knowledge in large language models (LLMs), and limited adaptability to dynamic document corpora. To address the issues, we propose a few-shot indexing-based GR framework (Few-Shot GR). It has a few-shot indexing process without any training, where we prompt an LLM to generate docids for all documents in a corpus, ultimately creating a docid bank for the entire corpus. During retrieval, we feed a query to the same LLM and constrain it to generate a docid within the docid bank created during indexing, and then map the generated docid back to its corresponding document. Moreover, we devise few-shot indexing with one-to-many mapping to further enhance Few-Shot GR. Experiments show that Few-Shot GR achieves superior performance to state-of-the-art GR methods requiring heavy training.

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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