序列模型是现代NLP系统的关键组成部分，但它们的预测难以解释。我们考虑虽然可以解释单个模型预测的基础，但是可以解释各种模型预测的上下文的模型解释。通过解决组合优化来找到顺序律师：最佳理由是输入令牌的最小子集，这些令牌将预测与完整序列相同的输出。枚举所有子集是棘手的，因此我们提出了一种高效的贪婪算法来近似这个目标。称为贪婪合理化的算法适用于任何模型。对于这种方法有效，模型应该在对上下文的不完整子集进行预测时形成兼容的条件分布。这种情况可以用短的微调步骤强制执行。我们研究语言建模与机器翻译的贪婪合理化。与现有的基线相比，贪婪合理化是最优化组合目标的，并提供最忠实的理由。在注释的顺序理由的新数据集中，贪婪的理由与人类理由最相似。

The word alignment task, despite its prominence in the era of statistical machine translation (SMT), is niche and under-explored today. In this two-part tutorial, we argue for the continued relevance for word alignment. The first part provides a historical background to word alignment as a core component of the traditional SMT pipeline. We zero-in on GIZA++, an unsupervised, statistical word aligner with surprising longevity. Jumping forward to the era of neural machine translation (NMT), we show how insights from word alignment inspired the attention mechanism fundamental to present-day NMT. The second part shifts to a survey approach. We cover neural word aligners, showing the slow but steady progress towards surpassing GIZA++ performance. Finally, we cover the present-day applications of word alignment, from cross-lingual annotation projection, to improving translation.

众所周知，端到端的神经NLP体系结构很难理解，这引起了近年来为解释性建模的许多努力。模型解释的基本原则是忠诚，即，解释应准确地代表模型预测背后的推理过程。这项调查首先讨论了忠诚的定义和评估及其对解释性的意义。然后，我们通过将方法分为五类来介绍忠实解释的最新进展：相似性方法，模型内部结构的分析，基于反向传播的方法，反事实干预和自我解释模型。每个类别将通过其代表性研究，优势和缺点来说明。最后，我们从它们的共同美德和局限性方面讨论了上述所有方法，并反思未来的工作方向忠实的解释性。对于有兴趣研究可解释性的研究人员，这项调查将为该领域提供可访问且全面的概述，为进一步探索提供基础。对于希望更好地了解自己的模型的用户，该调查将是一项介绍性手册，帮助选择最合适的解释方法。

Transfer learning, where a model is first pre-trained on a data-rich task before being finetuned on a downstream task, has emerged as a powerful technique in natural language processing (NLP). The effectiveness of transfer learning has given rise to a diversity of approaches, methodology, and practice. In this paper, we explore the landscape of transfer learning techniques for NLP by introducing a unified framework that converts all text-based language problems into a text-to-text format. Our systematic study compares pre-training objectives, architectures, unlabeled data sets, transfer approaches, and other factors on dozens of language understanding tasks. By combining the insights from our exploration with scale and our new "Colossal Clean Crawled Corpus", we achieve state-of-the-art results on many benchmarks covering summarization, question answering, text classification, and more. To facilitate future work on transfer learning for NLP, we release our data set, pre-trained models, and code.

当前的语言模型可以产生高质量的文本。他们只是复制他们之前看到的文本，或者他们学习了普遍的语言抽象吗？要取笑这些可能性，我们介绍了乌鸦，这是一套评估生成文本的新颖性，专注于顺序结构（n-gram）和句法结构。我们将这些分析应用于四种神经语言模型（LSTM，变压器，变换器-XL和GPT-2）。对于本地结构 - 例如，单个依赖性 - 模型生成的文本比来自每个模型的测试集的人类生成文本的基线显着不那么新颖。对于大规模结构 - 例如，总句结构 - 模型生成的文本与人生成的基线一样新颖甚至更新颖，但模型仍然有时复制，在某些情况下，在训练集中重复超过1000字超过1,000字的通道。我们还表现了广泛的手动分析，表明GPT-2的新文本通常在形态学和语法中形成良好，但具有合理的语义问题（例如，是自相矛盾）。

Large pretrained language models generate fluent text but are notoriously hard to controllably sample from. In this work, we study constrained sampling from such language models: generating text that satisfies user-defined constraints, while maintaining fluency and the model's performance in a downstream task. We propose MuCoLa -- a sampling procedure that combines the log-likelihood of the language model with arbitrary (differentiable) constraints in a single energy function, and then generates samples in a non-autoregressive manner. Specifically, it initializes the entire output sequence with noise and follows a Markov chain defined by Langevin Dynamics using the gradients of the energy function. We evaluate MuCoLa on text generation with soft and hard constraints as well as their combinations obtaining significant improvements over competitive baselines for toxicity avoidance, sentiment control, and keyword-guided generation.

We introduce a new language representation model called BERT, which stands for Bidirectional Encoder Representations from Transformers. Unlike recent language representation models (Peters et al., 2018a;Radford et al., 2018), BERT is designed to pretrain deep bidirectional representations from unlabeled text by jointly conditioning on both left and right context in all layers. As a result, the pre-trained BERT model can be finetuned with just one additional output layer to create state-of-the-art models for a wide range of tasks, such as question answering and language inference, without substantial taskspecific architecture modifications.BERT is conceptually simple and empirically powerful. It obtains new state-of-the-art results on eleven natural language processing tasks, including pushing the GLUE score to 80.5% (7.7% point absolute improvement), MultiNLI accuracy to 86.7% (4.6% absolute improvement), SQuAD v1.1 question answering Test F1 to 93.2 (1.5 point absolute improvement) and SQuAD v2.0 Test F1 to 83.1 (5.1 point absolute improvement).

Deep Learning and Machine Learning based models have become extremely popular in text processing and information retrieval. However, the non-linear structures present inside the networks make these models largely inscrutable. A significant body of research has focused on increasing the transparency of these models. This article provides a broad overview of research on the explainability and interpretability of natural language processing and information retrieval methods. More specifically, we survey approaches that have been applied to explain word embeddings, sequence modeling, attention modules, transformers, BERT, and document ranking. The concluding section suggests some possible directions for future research on this topic.

We present a novel approach to generating news headlines in Finnish for a given news story. We model this as a summarization task where a model is given a news article, and its task is to produce a concise headline describing the main topic of the article. Because there are no openly available GPT-2 models for Finnish, we will first build such a model using several corpora. The model is then fine-tuned for the headline generation task using a massive news corpus. The system is evaluated by 3 expert journalists working in a Finnish media house. The results showcase the usability of the presented approach as a headline suggestion tool to facilitate the news production process.

我用Hunglish2语料库训练神经电脑翻译任务的模型。这项工作的主要贡献在培训NMT模型期间评估不同的数据增强方法。我提出了5种不同的增强方法，这些方法是结构感知的，这意味着而不是随机选择用于消隐或替换的单词，句子的依赖树用作增强的基础。我首先关于神经网络的详细文献综述，顺序建模，神经机翻译，依赖解析和数据增强。经过详细的探索性数据分析和Hunglish2语料库的预处理之后，我使用所提出的数据增强技术进行实验。匈牙利语的最佳型号达到了33.9的BLEU得分，而英国匈牙利最好的模型达到了28.6的BLEU得分。

由于在开放式文本生成中取得了重大进展，衡量机器生成的文本是如何对人类语言的关键问题。我们介绍紫红色，一个开放式文本生成的比较措施，它直接将文本生成模型的学习分布与使用发散边界的分发进行了分布到人写的文本。淡紫色通过计算量化嵌入空间中的信息分流来缩放到现代文本生成模型。通过对三个开放式发电任务的广泛实证研究，我们发现紫红色标识了所生成文本的已知属性，天然存在模型大小，并与人类判断相关，而不是现有的分布评估度量的限制较少。

我们提出了一种可解释的关系提取方法，通过共同训练这两个目标来减轻概括和解释性之间的张力。我们的方法使用多任务学习体系结构，该体系结构共同训练分类器以进行关系提取，并在解释关系分类器的决策的关系中标记单词的序列模型。我们还将模型输出转换为规则，以将全局解释带入这种方法。使用混合策略对此序列模型进行训练：有监督，当可获得预先存在的模式的监督时，另外还要半监督。在后一种情况下，我们将序列模型的标签视为潜在变量，并学习最大化关系分类器性能的最佳分配。我们评估了两个数据集中的提议方法，并表明序列模型提供了标签，可作为关系分类器决策的准确解释，并且重要的是，联合培训通常可以改善关系分类器的性能。我们还评估了生成的规则的性能，并表明新规则是手动规则的重要附加功能，并使基于规则的系统更接近神经模型。

神经自回归序列模型涂抹许多可能​​序列之间的概率，包括退化的序列，例如空或重复序列。在这项工作中，我们解决了一个特定的情况，其中模型为不合理的短序列分配高概率。我们定义了量化速率以量化此问题。在确认神经机翻译中高度过度的过天气后，我们建议明确地减少培训期间的过天平率。我们进行一组实验来研究建议的正规化对模型分布和解码性能的影响。我们使用神经电脑翻译任务作为测试用，并考虑三个不同大小的不同数据集。我们的实验显示了三个主要结果。首先，我们可以通过调整正规化的强度来控制模型的过天平率。其次，通过提高过度损失贡献，令牌的概率和等级在不应该是它的位置下降。第三，所提出的正则化影响光束搜索的结果，特别是当使用大梁时。用大梁的翻译质量（在BLEU中测量）的降解显着减少了较低的过天速速率，但与较小光束尺寸相比的劣化仍有剩余状态。从这些观察中，我们得出结论，高度过度的过度性是神经自回归模型中过于可能的短序列的退化情况背后的主要原因。

Modern machine learning models are opaque, and as a result there is a burgeoning academic subfield on methods that explain these models' behavior. However, what is the precise goal of providing such explanations, and how can we demonstrate that explanations achieve this goal? Some research argues that explanations should help teach a student (either human or machine) to simulate the model being explained, and that the quality of explanations can be measured by the simulation accuracy of students on unexplained examples. In this work, leveraging meta-learning techniques, we extend this idea to improve the quality of the explanations themselves, specifically by optimizing explanations such that student models more effectively learn to simulate the original model. We train models on three natural language processing and computer vision tasks, and find that students trained with explanations extracted with our framework are able to simulate the teacher significantly more effectively than ones produced with previous methods. Through human annotations and a user study, we further find that these learned explanations more closely align with how humans would explain the required decisions in these tasks. Our code is available at https://github.com/coderpat/learning-scaffold

尽管变压器语言模型（LMS）是信息提取的最新技术，但长文本引入了需要次优的预处理步骤或替代模型体系结构的计算挑战。稀疏注意的LMS可以代表更长的序列，克服性能障碍。但是，目前尚不清楚如何解释这些模型的预测，因为并非所有令牌都在自我发项层中相互参加，而在运行时，长序列对可解释性算法提出了计算挑战，而当运行时取决于文档长度。这些挑战在文档可能很长的医学环境中是严重的，机器学习（ML）模型必须是审核和值得信赖的。我们介绍了一种新颖的蒙版抽样程序（MSP），以识别有助于预测的文本块，将MSP应用于预测医学文本诊断的背景下，并通过两位临床医生的盲目审查来验证我们的方法。我们的方法比以前的最先进的临床信息块高约1.7倍，速度更快100倍，并且可用于生成重要的短语对。 MSP特别适合长LMS，但可以应用于任何文本分类器。我们提供了MSP的一般实施。

随着越来越多的可用文本数据，能够自动分析，分类和摘要这些数据的算法的开发已成为必需品。在本研究中，我们提出了一种用于关键字识别的新颖算法，即表示给定文档的关键方面的一个或多字短语的提取，称为基于变压器的神经标记器，用于关键字识别（TNT-KID）。通过将变压器架构适用于手头的特定任务并利用域特定语料库上的预先磨损的语言模型，该模型能够通过提供竞争和强大的方式克服监督和无监督的最先进方法的缺陷在各种不同的数据集中的性能，同时仅需要最佳执行系统所需的手动标记的数据。本研究还提供了彻底的错误分析，具有对模型内部运作的有价值的见解和一种消融研究，测量关键字识别工作流程的特定组分对整体性能的影响。

我们提出了Pangu-Coder，这是一种仅预读的解码器语言模型，该模型采用pangu-alpha架构进行文本到代码生成，即给定自然语言问题描述的编程语言解决方案的合成。我们使用两阶段策略训练Pangu-Coder：第一阶段采用因果语言建模（CLM）来预先培训原始编程语言数据，而第二阶段则使用因果语言建模和掩盖语言建模（MLM）的组合培训目标，专注于文本到代码生成的下游任务，并培训松散的自然语言程序定义和代码功能。最后，我们讨论了pangu-coder-ft，该pander the是通过竞争性编程问题和代码与持续集成测试的结合进行了微调的。我们评估了pangu-coder，重点是它是否生成功能上正确的程序，并证明它在参加较小的上下文窗口和较少的数据培训的同时，它比诸如Codex之类的类似大小的模型（例如Codex）实现等效性或更好的性能。

Masked language modeling (MLM) pre-training methods such as BERT corrupt the input by replacing some tokens with [MASK] and then train a model to reconstruct the original tokens. While they produce good results when transferred to downstream NLP tasks, they generally require large amounts of compute to be effective. As an alternative, we propose a more sample-efficient pre-training task called replaced token detection. Instead of masking the input, our approach corrupts it by replacing some tokens with plausible alternatives sampled from a small generator network. Then, instead of training a model that predicts the original identities of the corrupted tokens, we train a discriminative model that predicts whether each token in the corrupted input was replaced by a generator sample or not. Thorough experiments demonstrate this new pre-training task is more efficient than MLM because the task is defined over all input tokens rather than just the small subset that was masked out. As a result, the contextual representations learned by our approach substantially outperform the ones learned by BERT given the same model size, data, and compute. The gains are particularly strong for small models; for example, we train a model on one GPU for 4 days that outperforms GPT (trained using 30x more compute) on the GLUE natural language understanding benchmark. Our approach also works well at scale, where it performs comparably to RoBERTa and XLNet while using less than 1/4 of their compute and outperforms them when using the same amount of compute.

在本文中，我们试图通过引入深度学习模型的句法归纳偏见来建立两所学校之间的联系。我们提出了两个归纳偏见的家族，一个家庭用于选区结构，另一个用于依赖性结构。选区归纳偏见鼓励深度学习模型使用不同的单位（或神经元）分别处理长期和短期信息。这种分离为深度学习模型提供了一种方法，可以从顺序输入中构建潜在的层次表示形式，即更高级别的表示由高级表示形式组成，并且可以分解为一系列低级表示。例如，在不了解地面实际结构的情况下，我们提出的模型学会通过根据其句法结构组成变量和运算符的表示来处理逻辑表达。另一方面，依赖归纳偏置鼓励模型在输入序列中找到实体之间的潜在关系。对于自然语言，潜在关系通常被建模为一个定向依赖图，其中一个单词恰好具有一个父节点和零或几个孩子的节点。将此约束应用于类似变压器的模型之后，我们发现该模型能够诱导接近人类专家注释的有向图，并且在不同任务上也优于标准变压器模型。我们认为，这些实验结果为深度学习模型的未来发展展示了一个有趣的选择。

将文本插入段落中指定位置的任务（称为空白（FITB））对于各种应用程序与作家与自然语言生成（NLG）系统互动以制作文本的应用很有用。虽然先前的工作已经通过专门培训的模型来解决此问题，但更有用的模型是可以有效地执行_both_ fitb和延续的模型。在这项工作中，我们评估了使用单个模型完成这两个任务的可行性。我们表明，通过FITB式目标进行预训练的模型都可以完成这两个任务，而预先训练的持续训练的模型却没有。最后，我们展示了如何轻松地对FITB模型进行填充，以允许对一代的长度和单词选择进行细粒度的控制。