arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1905.09438cs.CLcs.AIcs.NE
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基于深度强化学习的文档训练多跳阅读理解

Multi-hop Reading Comprehension via Deep Reinforcement Learning based Document Traversal

University of New South Wales(新南威尔士大学)

Alex Long, Joel Mason, Alan Blair, Wei Wang

摘要:

近年来,随着高质量的问答(QA)数据集的出现,阅读理解受到了极大的关注。尽管最先进的方法实现了强大的整体准确性,但多跳(MH)推理仍然特别具有挑战性。为了具体解决MH-QA问题,我们提出了一种基于深度强化学习的方法,该方法能够在大量文档集合中学习顺序推理,以便将查询感知的固定大小上下文子集传递给现有模型进行答案提取。我们的方法由两个阶段组成:一个链接器,它将提供的支持文档分解成句子图,和一个提取器,它根据当前问题和已经访问过的句子学习在哪里查找。链接器的结果是在句子级别上形成了一种新颖的图形结构,它保留了逻辑流,同时仍然允许在文档之间快速移动。重要的是,我们证明了所得到的图的稀疏性是不变的上下文大小。这意味着Deep-RL训练的提取器所需的决策更少,从而使系统能够有效地扩展到大型文档集合。在文档遍历步骤中顺序决策的重要性是通过与标准IE方法的比较来证明的,并且我们还引入了一个基于BM 25的IR基线,该基线仅检索与查询相关的文档。我们在最近提出的QAngaroo基准上研究了我们的方法与现有模型的集成,并实现了全面准确性的一致提高,以及训练时间的2- 3倍减少。

英文摘要:

Reading Comprehension has received significant attention in recent years as high quality Question Answering (QA) datasets have become available. Despite state-of-the-art methods achieving strong overall accuracy, Multi-Hop (MH) reasoning remains particularly challenging. To address MH-QA specifically, we propose a Deep Reinforcement Learning based method capable of learning sequential reasoning across large collections of documents so as to pass a query-aware, fixed-size context subset to existing models for answer extraction. Our method is comprised of two stages: a linker, which decomposes the provided support documents into a graph of sentences, and an extractor, which learns where to look based on the current question and already-visited sentences. The result of the linker is a novel graph structure at the sentence level that preserves logical flow while still allowing rapid movement between documents. Importantly, we demonstrate that the sparsity of the resultant graph is invariant to context size. This translates to fewer decisions required from the Deep-RL trained extractor, allowing the system to scale effectively to large collections of documents. The importance of sequential decision making in the document traversal step is demonstrated by comparison to standard IE methods, and we additionally introduce a BM25-based IR baseline that retrieves documents relevant to the query only. We examine the integration of our method with existing models on the recently proposed QAngaroo benchmark and achieve consistent increases in accuracy across the board, as well as a 2-3x reduction in training time.

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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