表中的信息可能是文本的重要补充,使基于表的问题答案(QA)具有巨大的价值。处理表的内在复杂性通常会增加模型设计和数据注释的额外负担。在本文中,我们旨在以最少的注释工作开发一个简单的基于表的质量检查模型。由于基于表的质量检查需要问题和表之间的对齐方式以及在多个表元素上执行复杂推理的能力,因此我们提出了一种杂食性的预读方法,该方法既可以消耗自然数据,又提出了合成数据,以使模型具有这些各自的能力。具体而言,鉴于可免费获得的表,我们利用检索将它们与相关的自然句子配对,以进行掩盖预处理,并通过将SQL从表中进行转换为QA损失进行预处理而合成NL问题。我们在几次和完整的设置中都进行了广泛的实验,结果清楚地证明了模型omnitab的优势,最好的多任务方法分别实现了16.2%和2.7%的绝对增益,在128次和完整的设置中也获得了2.7%建立有关Wickitable Questions的最新最新。详细的消融和分析揭示了自然和合成数据的不同特征,从而阐明了杂食性预处理的未来方向。可以在https://github.com/jzbjyb/omnitab上获得代码,预读数据和预算模型。
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学习捕获文本表对齐对于文本到SQL等任务至关重要。一个模型需要正确识别对列和值的自然语言引用,并在给定的数据库架构中将其扎根。在本文中,我们为文本到SQL提出了一个新颖的弱监督结构接地预处理框架(strug),可以有效地学习基于平行的文本表语料库来捕获文本表对齐。我们确定了一组新的预测任务:列接地,价值接地和列值映射,并利用它们为文本表编码预处理。此外,为了评估更现实的文本表对齐设置下的不同方法,我们基于蜘蛛dev设置的新评估集蜘蛛现实化,并明确提及已删除的列名,并采用八个现有的文本到SQL数据集以进行交叉 - 数据库评估。在所有设置中,Strug对Bert-Large都有显着改善。与现有的预训练方法(例如Grappa)相比,Strug在蜘蛛方面的性能相似,并且在更现实的集合上都优于所有基线。蜘蛛现实的数据集可从https://doi.org/10.5281/zenodo.5205322获得。
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Structured tabular data exist across nearly all fields. Reasoning task over these data aims to answer questions or determine the truthiness of hypothesis sentences by understanding the semantic meaning of a table. While previous works have devoted significant efforts to the tabular reasoning task, they always assume there are sufficient labeled data. However, constructing reasoning samples over tables (and related text) is labor-intensive, especially when the reasoning process is complex. When labeled data is insufficient, the performance of models will suffer an unendurable decline. In this paper, we propose a unified framework for unsupervised complex tabular reasoning (UCTR), which generates sufficient and diverse synthetic data with complex logic for tabular reasoning tasks, assuming no human-annotated data at all. We first utilize a random sampling strategy to collect diverse programs of different types and execute them on tables based on a "Program-Executor" module. To bridge the gap between the programs and natural language sentences, we design a powerful "NL-Generator" module to generate natural language sentences with complex logic from these programs. Since a table often occurs with its surrounding texts, we further propose novel "Table-to-Text" and "Text-to-Table" operators to handle joint table-text reasoning scenarios. This way, we can adequately exploit the unlabeled table resources to obtain a well-performed reasoning model under an unsupervised setting. Our experiments cover different tasks (question answering and fact verification) and different domains (general and specific), showing that our unsupervised methods can achieve at most 93% performance compared to supervised models. We also find that it can substantially boost the supervised performance in low-resourced domains as a data augmentation technique. Our code is available at https://github.com/leezythu/UCTR.
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Fact verification has attracted a lot of research attention recently, e.g., in journalism, marketing, and policymaking, as misinformation and disinformation online can sway one's opinion and affect one's actions. While fact-checking is a hard task in general, in many cases, false statements can be easily debunked based on analytics over tables with reliable information. Hence, table-based fact verification has recently emerged as an important and growing research area. Yet, progress has been limited due to the lack of datasets that can be used to pre-train language models (LMs) to be aware of common table operations, such as aggregating a column or comparing tuples. To bridge this gap, in this paper we introduce PASTA, a novel state-of-the-art framework for table-based fact verification via pre-training with synthesized sentence-table cloze questions. In particular, we design six types of common sentence-table cloze tasks, including Filter, Aggregation, Superlative, Comparative, Ordinal, and Unique, based on which we synthesize a large corpus consisting of 1.2 million sentence-table pairs from WikiTables. PASTA uses a recent pre-trained LM, DeBERTaV3, and further pretrains it on our corpus. Our experimental results show that PASTA achieves new state-of-the-art performance on two table-based fact verification benchmarks: TabFact and SEM-TAB-FACTS. In particular, on the complex set of TabFact, which contains multiple operations, PASTA largely outperforms the previous state of the art by 4.7 points (85.6% vs. 80.9%), and the gap between PASTA and human performance on the small TabFact test set is narrowed to just 1.5 points (90.6% vs. 92.1%).
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最近的语言模型预培训进展取得了巨大的成功,通过利用大规模的非结构化文本数据。然而,由于没有大规模的高质量表格数据,在结构化的表格数据上应用预先培训仍然是一项挑战。在本文中,我们提出了Tapex,以表明通过在合成语料库上学习神经SQL执行程序来实现表预培训,这是通过自动合成可执行的SQL查询和执行输出来获得的。 Tapex通过引导语言模型来模仿SQL执行程序的不同,大规模和高质量的合成语料库来解决数据稀缺性挑战。我们在四个基准数据集中评估Tapex。实验结果表明,Tapex优于以前的表格预训练,并通过大幅度达到了新的最先进的结果。这包括改进弱监管的WikiSQL表示精度为89.5%(+ 2.3%),WikityQuestions表示精度为57.5%(+ 4.8%),SQA表示精度为74.5%(+ 3.5%)和Tabfact精度84.2%(+ 3.2%)。为了我们的知识,这是通过合成可执行程序利用表预培训的第一项工作,并在各种下游任务上实现新的最先进结果。
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Open-domain question answering relies on efficient passage retrieval to select candidate contexts, where traditional sparse vector space models, such as TF-IDF or BM25, are the de facto method. In this work, we show that retrieval can be practically implemented using dense representations alone, where embeddings are learned from a small number of questions and passages by a simple dualencoder framework. When evaluated on a wide range of open-domain QA datasets, our dense retriever outperforms a strong Lucene-BM25 system greatly by 9%-19% absolute in terms of top-20 passage retrieval accuracy, and helps our end-to-end QA system establish new state-of-the-art on multiple open-domain QA benchmarks. 1 * Equal contribution 1 The code and trained models have been released at https://github.com/facebookresearch/DPR.
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Systems for knowledge-intensive tasks such as open-domain question answering (QA) usually consist of two stages: efficient retrieval of relevant documents from a large corpus and detailed reading of the selected documents to generate answers. Retrievers and readers are usually modeled separately, which necessitates a cumbersome implementation and is hard to train and adapt in an end-to-end fashion. In this paper, we revisit this design and eschew the separate architecture and training in favor of a single Transformer that performs Retrieval as Attention (ReAtt), and end-to-end training solely based on supervision from the end QA task. We demonstrate for the first time that a single model trained end-to-end can achieve both competitive retrieval and QA performance, matching or slightly outperforming state-of-the-art separately trained retrievers and readers. Moreover, end-to-end adaptation significantly boosts its performance on out-of-domain datasets in both supervised and unsupervised settings, making our model a simple and adaptable solution for knowledge-intensive tasks. Code and models are available at https://github.com/jzbjyb/ReAtt.
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知识密集型语言任务(苏格兰信)通常需要大量信息来提供正确的答案。解决此问题的一种流行范式是将搜索系统与机器读取器相结合,前者检索支持证据,后者检查它们以产生答案。最近,读者组成部分在大规模预培养的生成模型的帮助下见证了重大进展。同时,搜索组件中的大多数现有解决方案都依赖于传统的``索引 - retrieve-then-Rank''管道,该管道遭受了巨大的内存足迹和端到端优化的困难。受到最新构建基于模型的IR模型的努力的启发,我们建议用新颖的单步生成模型替换传统的多步搜索管道,该模型可以极大地简化搜索过程并以端到端的方式进行优化。我们表明,可以通过一组经过适当设计的预训练任务来学习强大的生成检索模型,并被采用以通过进一步的微调来改善各种下游苏格兰短裙任务。我们将预训练的生成检索模型命名为Copusbrain,因为有关该语料库的所有信息均以其参数进行编码,而无需构造其他索引。经验结果表明,在苏格兰语基准上的检索任务并建立了新的最新性能,Copusbrain可以极大地超过强大的基准。我们还表明,在零农源和低资源设置下,科体班运行良好。
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文本到SQL解析是一项必不可少且具有挑战性的任务。文本到SQL解析的目的是根据关系数据库提供的证据将自然语言(NL)问题转换为其相应的结构性查询语言(SQL)。来自数据库社区的早期文本到SQL解析系统取得了显着的进展,重度人类工程和用户与系统的互动的成本。近年来,深层神经网络通过神经生成模型显着提出了这项任务,该模型会自动学习从输入NL问题到输出SQL查询的映射功能。随后,大型的预训练的语言模型将文本到SQL解析任务的最新作品带到了一个新级别。在这项调查中,我们对文本到SQL解析的深度学习方法进行了全面的评论。首先,我们介绍了文本到SQL解析语料库,可以归类为单转和多转。其次,我们提供了预先训练的语言模型和现有文本解析方法的系统概述。第三,我们向读者展示了文本到SQL解析所面临的挑战,并探索了该领域的一些潜在未来方向。
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Natural Language Generation (NLG) has improved exponentially in recent years thanks to the development of sequence-to-sequence deep learning technologies such as Transformer-based language models. This advancement has led to more fluent and coherent NLG, leading to improved development in downstream tasks such as abstractive summarization, dialogue generation and data-to-text generation. However, it is also apparent that deep learning based generation is prone to hallucinate unintended text, which degrades the system performance and fails to meet user expectations in many real-world scenarios. To address this issue, many studies have been presented in measuring and mitigating hallucinated texts, but these have never been reviewed in a comprehensive manner before. In this survey, we thus provide a broad overview of the research progress and challenges in the hallucination problem in NLG. The survey is organized into two parts: (1) a general overview of metrics, mitigation methods, and future directions; and (2) an overview of task-specific research progress on hallucinations in the following downstream tasks, namely abstractive summarization, dialogue generation, generative question answering, data-to-text generation, machine translation, and visual-language generation. This survey serves to facilitate collaborative efforts among researchers in tackling the challenge of hallucinated texts in NLG.
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Entities, as important carriers of real-world knowledge, play a key role in many NLP tasks. We focus on incorporating entity knowledge into an encoder-decoder framework for informative text generation. Existing approaches tried to index, retrieve, and read external documents as evidence, but they suffered from a large computational overhead. In this work, we propose an encoder-decoder framework with an entity memory, namely EDMem. The entity knowledge is stored in the memory as latent representations, and the memory is pre-trained on Wikipedia along with encoder-decoder parameters. To precisely generate entity names, we design three decoding methods to constrain entity generation by linking entities in the memory. EDMem is a unified framework that can be used on various entity-intensive question answering and generation tasks. Extensive experimental results show that EDMem outperforms both memory-based auto-encoder models and non-memory encoder-decoder models.
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实际一致性是实际设置中文本摘要模型的基本质量。在评估此维度的现有工作可以大致分为两行研究,基于征收的指标和问题应答(QA)的指标。然而,最近作品中提出的不同的实验设置导致对比的结论是哪个范例表现最佳。在这项工作中,我们进行了广泛的征集和基于QA的指标的比较,致力于仔细选择基于QA的度量的组件对于性能至关重要。在那些见解中,我们提出了一个优化的公制,我们称之为QAFacteval,这导致了对夏季事实一致性基准的基于QA的度量标准的平均平均平均改进。我们的解决方案提高了基于最佳的基于范围的公制,并在该基准测试中实现了最先进的性能。此外,我们发现基于QA和基于征求的度量提供了互补信号,并将两者组合成单个学习的度量,以进一步提升。通过定性和定量分析,我们将问题生成和可应答性分类视为基于QA的度量的未来工作的两个关键组成部分。
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临床问题应答(QA)旨在根据临床文本自动回答医疗专业人员的问题。研究表明,在一个语料库上培训的神经QA模型可能对来自不同研究所或不同患者组的新临床文本概括,其中大规模的QA对不容易获得模型再培训。为了解决这一挑战,我们提出了一个简单但有效的框架CliniQG4QA,它利用问题生成(QG)在新的临床环境中综合QA对,并在不需要手动注释的情况下提升QA模型。为了生成对训练QA模型至关重要的不同类型的问题,我们进一步引入了基于SEQ2SEQ的问题短语预测(QPP)模块,可以与大多数现有的QG模型一起使用以使生成多样化。我们的综合实验结果表明,我们的框架产生的QA​​语料库可以改善新上下文的QA模型(在完全匹配方面最高8%的绝对增益),QPP模块在实现增益方面发挥着至关重要的作用。
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自动问题应答(QA)系统的目的是以时间有效的方式向用户查询提供答案。通常在数据库(或知识库)或通常被称为语料库的文件集合中找到答案。在过去的几十年里,收购知识的扩散,因此生物医学领域的新科学文章一直是指数增长。因此,即使对于领域专家,也难以跟踪域中的所有信息。随着商业搜索引擎的改进,用户可以在某些情况下键入其查询并获得最相关的一小组文档,以及在某些情况下从文档中的相关片段。但是,手动查找所需信息或答案可能仍然令人疑惑和耗时。这需要开发高效的QA系统,该系统旨在为用户提供精确和精确的答案提供了生物医学领域的自然语言问题。在本文中,我们介绍了用于开发普通域QA系统的基本方法,然后彻底调查生物医学QA系统的不同方面,包括使用结构化数据库和文本集合的基准数据集和几种提出的方​​法。我们还探讨了当前系统的局限性,并探索潜在的途径以获得进一步的进步。
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预训练的语言模型(PTLM)已显示出在自然语言任务上表现良好。许多先前的作品都以通过知识图(KGS)标记的关系链接的实体的形式利用结构性常识来协助PTLM。检索方法使用kg作为单独的静态模块,该模块限制了覆盖范围,因为kgs包含有限的知识。生成方法训练PTLMS kg三倍以提高获得知识的规模。但是,对符号KG实体的培训限制了其在涉及自然语言文本的任务中的适用性,在这些任务中,它们忽略了整体上下文。为了减轻这种情况,我们提出了一个以句子为条件的常识性上下文化器(COSE-CO)作为输入,以使其在生成与输入文本的整体上下文相关的任务中通常可用。为了训练Cose-Co,我们提出了一个新的数据集,其中包括句子和常识知识对。 COSE-CO推断出的知识是多种多样的,并且包含了基础KG中不存在的新实体。我们增强了在多选质量质量检查和开放式常识性推理任务中产生的知识,从而改善了CSQA,ARC,QASC和OBQA数据集的当前最佳方法。我们还展示了其在改善释义生成任务的基线模型方面的适用性。
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随着未来以数据为中心的决策,对数据库的无缝访问至关重要。关于创建有效的文本到SQL(Text2SQL)模型以访问数据库的数据有广泛的研究。使用自然语言是可以通过有效访问数据库(尤其是对于非技术用户)来弥合数据和结果之间差距的最佳接口之一。它将打开门,并在精通技术技能或不太熟练的查询语言的用户中引起极大的兴趣。即使提出或研究了许多基于深度学习的算法,在现实工作场景中使用自然语言来解决数据查询问题仍然非常具有挑战性。原因是在不同的研究中使用不同的数据集,这带来了其局限性和假设。同时,我们确实缺乏对这些提议的模型及其对其训练的特定数据集的局限性的彻底理解。在本文中,我们试图介绍过去几年研究的24种神经网络模型的整体概述,包括其涉及卷积神经网络,经常性神经网络,指针网络,强化学习,生成模型等的架构。我们还概述11个数据集,这些数据集被广泛用于训练Text2SQL技术的模型。我们还讨论了无缝数据查询中文本2SQL技术的未来应用可能性。
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In long document controllable summarization, where labeled data is scarce, pretrained models struggle to adapt to the task and effectively respond to user queries. In this paper, we introduce Socratic pretraining, a question-driven, unsupervised pretraining objective specifically designed to improve controllability in summarization tasks. By training a model to generate and answer relevant questions in a given context, Socratic pretraining enables the model to more effectively adhere to user-provided queries and identify relevant content to be summarized. We demonstrate the effectiveness of this approach through extensive experimentation on two summarization domains, short stories and dialogue, and multiple control strategies: keywords, questions, and factoid QA pairs. Our pretraining method relies only on unlabeled documents and a question generation system and outperforms pre-finetuning approaches that use additional supervised data. Furthermore, our results show that Socratic pretraining cuts task-specific labeled data requirements in half, is more faithful to user-provided queries, and achieves state-of-the-art performance on QMSum and SQuALITY.
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知识基础问题回答(KBQA)旨在通过知识库(KB)回答问题。早期研究主要集中于回答有关KB的简单问题,并取得了巨大的成功。但是,他们在复杂问题上的表现远非令人满意。因此,近年来,研究人员提出了许多新颖的方法,研究了回答复杂问题的挑战。在这项调查中,我们回顾了KBQA的最新进展,重点是解决复杂问题,这些问题通常包含多个主题,表达复合关系或涉及数值操作。详细说明,我们从介绍复杂的KBQA任务和相关背景开始。然后,我们描述用于复杂KBQA任务的基准数据集,并介绍这些数据集的构建过程。接下来,我们提出两个复杂KBQA方法的主流类别,即基于语义解析的方法(基于SP)的方法和基于信息检索的方法(基于IR)。具体而言,我们通过流程设计说明了他们的程序,并讨论了它们的主要差异和相似性。之后,我们总结了这两类方法在回答复杂问题时会遇到的挑战,并解释了现有工作中使用的高级解决方案和技术。最后,我们结论并讨论了与复杂的KBQA有关的几个有希望的方向,以进行未来的研究。
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预审前的语言模型通过提供高质量的上下文化单词嵌入来显着改善了下游语言理解任务(包括提取性问题)的性能。但是,培训问答模型仍然需要大量特定域的注释数据。在这项工作中,我们提出了一个合作的自我训练框架RGX,用于自动生成更非平凡的问题 - 解答对以提高模型性能。 RGX建立在带有答案实体识别器,问题生成器和答案提取器的交互式学习环境的蒙版答案提取任务上。给定带有蒙版实体的段落,生成器会在实体周围生成一个问题,并培训了提取器,以提取蒙面实体,并使用生成的问题和原始文本。该框架允许对任何文本语料库的问题产生和回答模型进行培训,而无需注释。实验结果表明,RGX优于最先进的语言模型(SOTA)的语言模型,并在标准提问基准的基准上采用转移学习方法,并在给定的模型大小和传输学习设置下产生新的SOTA性能。
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检索增强的代表在许多知识密集型的NLP任务中表现出最先进的表现,例如打开问题应答和事实验证。考虑到检索到的段落,这些模型训练以产生最终输出,这可能与原始查询无关,导致学习虚假线索或回答记忆。这项工作介绍了一种融入通道的证据性的方法 - 是否段落包含正确的证据来支持输出 - 培训发电机。我们介绍了一个多任务学习框架,共同生成最终输出并预测每个段落的证据性,利用新的任务不可行方法来获得{\ IT Silver}分证分性标签进行监督。我们在三个知识密集型任务中的五个数据集的实验表明,我们的新的证据引导发电机具有相同尺寸模型的直接对应的直接对应,并使Faviq-Ambig的最先进。我们将这些改进归因于辅助多任务学习和银证处分性挖掘技术。
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