具有复制机制的最近神经序列到序列模型在各种文本生成任务中取得了显着的进展。这些模型解决了词汇问题，并促进了稀有词的产生。然而，如先前的复制模型所观察到的，难以产生的，难以产生和缺乏抽象，难以识别。在本文中，我们提出了一种副本网络的新颖监督方法，该方法可帮助模型决定需要复制哪些单词并需要生成。具体而言，我们重新定义目标函数，它利用源序列和目标词汇表作为复制的指导。关于数据到文本生成和抽象总结任务的实验结果验证了我们的方法提高了复制质量，提高了抽象程度。

Neural sequence-to-sequence models have provided a viable new approach for abstractive text summarization (meaning they are not restricted to simply selecting and rearranging passages from the original text). However, these models have two shortcomings: they are liable to reproduce factual details inaccurately, and they tend to repeat themselves. In this work we propose a novel architecture that augments the standard sequence-to-sequence attentional model in two orthogonal ways. First, we use a hybrid pointer-generator network that can copy words from the source text via pointing, which aids accurate reproduction of information, while retaining the ability to produce novel words through the generator. Second, we use coverage to keep track of what has been summarized, which discourages repetition. We apply our model to the CNN / Daily Mail summarization task, outperforming the current abstractive state-of-the-art by at least 2 ROUGE points.

In this work, we model abstractive text summarization using Attentional Encoder-Decoder Recurrent Neural Networks, and show that they achieve state-of-the-art performance on two different corpora. We propose several novel models that address critical problems in summarization that are not adequately modeled by the basic architecture, such as modeling key-words, capturing the hierarchy of sentence-toword structure, and emitting words that are rare or unseen at training time. Our work shows that many of our proposed models contribute to further improvement in performance. We also propose a new dataset consisting of multi-sentence summaries, and establish performance benchmarks for further research.

Nowadays, time-stamped web documents related to a general news query floods spread throughout the Internet, and timeline summarization targets concisely summarizing the evolution trajectory of events along the timeline. Unlike traditional document summarization, timeline summarization needs to model the time series information of the input events and summarize important events in chronological order. To tackle this challenge, in this paper, we propose a Unified Timeline Summarizer (UTS) that can generate abstractive and extractive timeline summaries in time order. Concretely, in the encoder part, we propose a graph-based event encoder that relates multiple events according to their content dependency and learns a global representation of each event. In the decoder part, to ensure the chronological order of the abstractive summary, we propose to extract the feature of event-level attention in its generation process with sequential information remained and use it to simulate the evolutionary attention of the ground truth summary. The event-level attention can also be used to assist in extracting summary, where the extracted summary also comes in time sequence. We augment the previous Chinese large-scale timeline summarization dataset and collect a new English timeline dataset. Extensive experiments conducted on these datasets and on the out-of-domain Timeline 17 dataset show that UTS achieves state-of-the-art performance in terms of both automatic and human evaluations.

We introduce extreme summarization, a new single-document summarization task which does not favor extractive strategies and calls for an abstractive modeling approach. The idea is to create a short, one-sentence news summary answering the question "What is the article about?". We collect a real-world, large scale dataset for this task by harvesting online articles from the British Broadcasting Corporation (BBC). We propose a novel abstractive model which is conditioned on the article's topics and based entirely on convolutional neural networks. We demonstrate experimentally that this architecture captures longrange dependencies in a document and recognizes pertinent content, outperforming an oracle extractive system and state-of-the-art abstractive approaches when evaluated automatically and by humans. 1

与单案摘要相比，抽象性多文件摘要（MDS）对其冗长和链接的来源的表示和覆盖范围提出了挑战。这项研究开发了一个平行的层次变压器（PHT），具有MDS的注意对齐。通过合并单词和段落级的多头注意，PHT的层次结构可以更好地处理令牌和文档级别的依赖项。为了指导解码到更好的源文档覆盖范围，然后将注意力调整机制引入以校准光束搜索，并预测的最佳注意力分布。根据Wikisum数据，进行了全面的评估，以测试拟议的体系结构对MD的改进。通过更好地处理内部和跨文档的信息，结果胭脂和人类评估都表明，我们的分层模型以相对较低的计算成本生成较高质量的摘要。

复制机制允许序列到序列模型从输入中选择单词并将它们直接放入输出中，这在抽象总结中发现越来越多的使用。但是，由于汉语句子中没有明确的分隔符，所以最现有的中国抽象摘要模型只能执行字符副本，从而导致效率低下。为了解决这个问题，我们提出了一个词典约束的复制网络，在编码器和解码器中模拟多粒度。在源端，单词和字符使用变换器基编码器聚合到相同的输入存储器中。在目标方面，解码器可以在每个时间步骤复制字符或多字符字，并且解码过程由一个词增强的搜索算法引导，其促进并行计算并鼓励模型复制更多单词。此外，我们采用单词选择器来集成关键字信息。实验结果在中国社交媒体数据集显示我们的模型可以独立或使用单词选择器。这两种形式都可以胜过以前的基于角色的模型并实现竞争性表现。

尽管最近的抽象性摘要在自动评估指标上取得了成功，但生成的摘要仍然与源文档呈现事实不一致。在本文中，我们专注于实体级别的事实不一致，即减少生成的摘要与源文档之间的不匹配实体。因此，我们提出了一种基于实体的新型跨度机制，并通过全球相关成分探索其扩展。四个摘要数据集的实验结果表明，跨度可以有效地改善实体级别的事实一致性，而单词级别和实体级别的显着性基本上没有变化。该代码可在https://github.com/wendy-xiao/entity基于基础上找到

Bidirectional Encoder Representations from Transformers (BERT; Devlin et al. 2019) represents the latest incarnation of pretrained language models which have recently advanced a wide range of natural language processing tasks. In this paper, we showcase how BERT can be usefully applied in text summarization and propose a general framework for both extractive and abstractive models. We introduce a novel document-level encoder based on BERT which is able to express the semantics of a document and obtain representations for its sentences. Our extractive model is built on top of this encoder by stacking several intersentence Transformer layers. For abstractive summarization, we propose a new fine-tuning schedule which adopts different optimizers for the encoder and the decoder as a means of alleviating the mismatch between the two (the former is pretrained while the latter is not). We also demonstrate that a two-staged fine-tuning approach can further boost the quality of the generated summaries. Experiments on three datasets show that our model achieves stateof-the-art results across the board in both extractive and abstractive settings. 1

Summarization based on text extraction is inherently limited, but generation-style abstractive methods have proven challenging to build. In this work, we propose a fully data-driven approach to abstractive sentence summarization. Our method utilizes a local attention-based model that generates each word of the summary conditioned on the input sentence. While the model is structurally simple, it can easily be trained end-to-end and scales to a large amount of training data. The model shows significant performance gains on the DUC-2004 shared task compared with several strong baselines.

We introduce an approach for the answer-aware question generation problem. Instead of only relying on the capability of strong pre-trained language models, we observe that the information of answers and questions can be found in some relevant sentences in the context. Based on that, we design a model which includes two modules: a selector and a generator. The selector forces the model to more focus on relevant sentences regarding an answer to provide implicit local information. The generator generates questions by implicitly combining local information from the selector and global information from the whole context encoded by the encoder. The model is trained jointly to take advantage of latent interactions between the two modules. Experimental results on two benchmark datasets show that our model is better than strong pre-trained models for the question generation task. The code is also available (shorturl.at/lV567).

通过言语技术的最新进步和智能助理的引入，如亚马逊Alexa，Apple Siri和Google Home，越来越多的用户通过语音命令与各种应用程序进行交互。电子商务公司通常在其网页上显示较短的产品标题，在需要简洁时，可以在其网页上进行人工策划或算法生成。然而，这些标题与自然语言不同。例如，“幸运的魅力面筋无麸质谷物，20.5盎司盒装幸运魅力含有无麸质”可以在网页上显示，而在基于语音的文本到语音应用程序中不能使用类似的标题。在这种对话系统中，易于理解的句子，例如“20.5盎司的幸运魅力麸质谷物”是优选的。与显示设备相比，可以向用户呈现图像和详细的产品信息，在与语音助手相互作用时，需要传达最重要信息的产品的短标题。我们提出Ebert，通过进一步预先训练电子商务产品描述语料库中的BERT嵌入来进行序列到序列方法，然后微调结果模型，以产生来自输入Web标题的短，自然的语言标题。我们对现实世界行业数据集的广泛实验，以及对模型输出的人类评估，表明Ebert摘要优于相当的基线模型。由于该模型的功效，该模型的版本已在真实世界中进行部署。

上下文：堆栈溢出对于寻求编程问题答案的软件开发人员非常有帮助。先前的研究表明，越来越多的问题质量低，因此从潜在的答案者那里获得了更少的关注。 Gao等。提出了一个基于LSTM的模型（即BilstM-CC），以自动从代码片段中生成问题标题，以提高问题质量。但是，只有在问题主体中使用代码段无法为标题生成提供足够的信息，而LSTMS无法捕获令牌之间的远程依赖性。目的：本文提出了基于深度学习的新型模型CCBERT，旨在通过充分利用整个问题主体的双模式信息来增强问题标题生成的性能。方法：CCBERT遵循编码器范式范式，并使用Codebert将问题主体编码为隐藏的表示形式，堆叠的变压器解码器以生成预测的代币，以及附加的复制注意层来完善输出分布。编码器和解码器都执行多头自我注意操作，以更好地捕获远程依赖性。本文构建了一个数据集，该数据集包含大约200,000个高质量问题，该数据从Stack Overflow正式发布的数据中滤除，以验证CCBERT模型的有效性。结果：CCBERT优于数据集上的所有基线模型。对仅代码和低资源数据集进行的实验表明，CCBERT的优势性能较小。人类评估还显示了CCBERT关于可读性和相关标准的出色表现。

对话摘要已被广泛研究和应用，其中，先前的作品主要集中在探索卓越的模型结构方面，以对准输入对话和输出摘要。然而，对于专业对话（例如，法律辩论和医学诊断），语义/统计对齐可能几乎不会填补输入对话话语话语和外部知识的摘要输出之间的逻辑/事实差距。在本文中，我们主要研究了非预介绍和预用环境下对话检验摘要（DIS）的事实不一致问题。创新的端到端对话摘要生成框架是有两个辅助任务：预期事实方面正规化（EFAR）和缺少事实实体歧视（MFED）。综合实验表明，该模型可以以准确的事实方面的覆盖率来产生更可读的总结，以及通知用户从输入对话中检测到的潜在缺失事实以获得进一步的人为干预。

对比学习模型在无监督的视觉表示学习中取得了巨大成功，这使得相同图像的不同视图的特征表示之间的相似性最大化，同时最小化不同图像的视图的特征表示之间的相似性。在文本摘要中，输出摘要是输入文档的较短形式，它们具有类似的含义。在本文中，我们提出了对监督抽象文本摘要的对比学习模型，在那里我们查看文档，它的金摘要及其模型生成的摘要，与相同的平均表示的不同视图，并在培训期间最大化它们之间的相似性。我们在三个不同的摘要数据集上改进了一个强序列到序列文本生成模型（即，BART）。人类评估还表明，与其对应物相比，我们的模型达到了更好的忠实性评级，没有对比的目标。

本文对过去二十年来对自然语言生成（NLG）的研究提供了全面的审查，特别是与数据到文本生成和文本到文本生成深度学习方法有关，以及NLG的新应用技术。该调查旨在（a）给出关于NLG核心任务的最新综合，以及该领域采用的建筑;（b）详细介绍各种NLG任务和数据集，并提请注意NLG评估中的挑战，专注于不同的评估方法及其关系;（c）强调一些未来的强调和相对近期的研究问题，因为NLG和其他人工智能领域的协同作用而增加，例如计算机视觉，文本和计算创造力。

尽管具有抽象文本摘要的神经序列到序列模型的成功，但它具有一些缺点，例如重复不准确的事实细节并倾向于重复自己。我们提出了一个混合指针发生器网络，以解决再现事实细节的缺点和短语重复。我们使用混合指针发生器网络增强了基于注意的序列到序列，该混合指针发生器网络可以生成词汇单词并增强再现真实细节的准确性和劝阻重复的覆盖机制。它产生合理的输出文本，可以保留输入文章的概念完整性和事实信息。为了评估，我们主要雇用“百拉那” - 一个高度采用的公共孟加拉数据集。此外，我们准备了一个名为“BANS-133”的大型数据集，由133K Bangla新闻文章组成，与人类生成的摘要相关。试验拟议的模型，我们分别实现了胭脂-1和胭脂 - 2分别为0.66,0.41的“Bansdata”数据集，分别为0.67,0.42，为Bans-133k“数据集。我们证明了所提出的系统超过以前的国家 - 近距离数据集的近距离攀义概要技术及其稳定性。“Bans-133”数据集和代码基础将公开进行研究。

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.

现有的抽象摘要模型缺乏明确的控制机制，允许用户影响模型输出的风格特征。这导致生成不迎合用户需求或偏好的通用摘要。为了解决这个问题，我们介绍了Hydrasum，这是一种新的摘要架构，其扩展了当前模型的单个解码器框架，例如， BART，到专家的混合版本，包括多个解码器。我们拟议的模型鼓励每个专家，即解码器，沿着尺寸学习和生成风格不同的摘要，例如抽象，长度，特异性等。在每个时间步骤中，Hydrasum采用一个门控机制，该机构决定每个单独解码器对下一个令牌的输出概率分布的贡献。通过对三个摘要数据集的实验（CNN，新闻编辑室，XSUM），我们证明了这种门控机制自动学习在标准培训目标下将对比摘要样式分配给不同的水路解码器，而无需额外监督。我们进一步表明，培训过程的指导版本可以明确地管理哪些摘要样式在解码器之间分区，例如，高抽象力与低吸引力或高特异性与低特异性，并且还增加各个解码器之间的致命差异。最后，我们的实验表明，我们的解码器框架非常灵活：在推理期间，我们可以从单独的解码器或解码器的不同子集的混合物中进行采样，以产生多种摘要，并强制对摘要生成的单一和多样式控制。

ROUGE is a standard automatic evaluation metric based on n-grams for sequence-to-sequence tasks, while cross-entropy loss is an essential objective of neural network language model that optimizes at a unigram level. We present differentiable n-gram objectives, attempting to alleviate the discrepancy between training criterion and evaluating criterion. The objective maximizes the probabilistic weight of matched sub-sequences, and the novelty of our work is the objective weights the matched sub-sequences equally and does not ceil the number of matched sub-sequences by the ground truth count of n-grams in reference sequence. We jointly optimize cross-entropy loss and the proposed objective, providing decent ROUGE score enhancement over abstractive summarization dataset CNN/DM and XSum, outperforming alternative n-gram objectives.