arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2104.08443cs.CLcs.IR
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一种基于图引导的开放领域会话问答多轮检索方法

A Graph-guided Multi-round Retrieval Method for Conversational Open-domain Question Answering

The Hong Kong Polytechnic University(香港理工大学);Shandong University(山东大学)

Yongqi Li, Wenjie Li, Liqiang Nie

摘要:

近年来,会话智能体为人们提供了一种自然、便捷的获取信息的途径,会话问答(QA)也成为一个新的研究课题。在当前流行的会话式问答任务中,会话式开放域问答(英语:Conversational open-domain QA)要求从Web上检索相关段落以提取准确答案,是一种实用性较强但研究较少的问答任务。如何更好地捕捉和充分挖掘会话中的历史语境,以利于有效的大规模检索,这是一个主要的挑战。目前的研究主要是利用历史问题来提炼当前问题或增强其代表性,而历史答案和当前答案之间的关系,这也是这项任务的关键,是完全被忽视的。为了解决这个问题,我们提出了一种新的图引导检索方法来模拟会话轮之间的答案之间的关系。特别是,它利用了一个通道图从超链接连接的段落,包含历史答案和潜在的当前答案,检索更多的相关段落,为后续的答案提取。此外,为了在历史语境中收集更多的互补信息,我们还建议结合多轮相关反馈技术来探讨检索语境对当前问题理解的影响。在公开数据集上的实验结果验证了该方法的有效性。值得注意的是,预测历史答案和真实历史答案的F1分数分别提高了5%和11%。

英文摘要:

In recent years, conversational agents have provided a natural and convenient access to useful information in people's daily life, along with a broad and new research topic, conversational question answering (QA). Among the popular conversational QA tasks, conversational open-domain QA, which requires to retrieve relevant passages from the Web to extract exact answers, is more practical but less studied. The main challenge is how to well capture and fully explore the historical context in conversation to facilitate effective large-scale retrieval. The current work mainly utilizes history questions to refine the current question or to enhance its representation, yet the relations between history answers and the current answer in a conversation, which is also critical to the task, are totally neglected. To address this problem, we propose a novel graph-guided retrieval method to model the relations among answers across conversation turns. In particular, it utilizes a passage graph derived from the hyperlink-connected passages that contains history answers and potential current answers, to retrieve more relevant passages for subsequent answer extraction. Moreover, in order to collect more complementary information in the historical context, we also propose to incorporate the multi-round relevance feedback technique to explore the impact of the retrieval context on current question understanding. Experimental results on the public dataset verify the effectiveness of our proposed method. Notably, the F1 score is improved by 5% and 11% with predicted history answers and true history answers, respectively.

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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