The distributed representation of symbols is one of the key technologies in machine learning systems today, playing a pivotal role in modern natural language processing. Traditional word embeddings associate a separate vector with each word. While this approach is simple and leads to good performance, it requires a lot of memory for representing a large vocabulary. To reduce the memory footprint, the default embedding layer in spaCy is a hash embeddings layer. It is a stochastic approximation of traditional embeddings that provides unique vectors for a large number of words without explicitly storing a separate vector for each of them. To be able to compute meaningful representations for both known and unknown words, hash embeddings represent each word as a summary of the normalized word form, subword information and word shape. Together, these features produce a multi-embedding of a word. In this technical report we lay out a bit of history and introduce the embedding methods in spaCy in detail. Second, we critically evaluate the hash embedding architecture with multi-embeddings on Named Entity Recognition datasets from a variety of domains and languages. The experiments validate most key design choices behind spaCy's embedders, but we also uncover a few surprising results.

Named entity recognition models (NER), are widely used for identifying named entities (e.g., individuals, locations, and other information) in text documents. Machine learning based NER models are increasingly being applied in privacy-sensitive applications that need automatic and scalable identification of sensitive information to redact text for data sharing. In this paper, we study the setting when NER models are available as a black-box service for identifying sensitive information in user documents and show that these models are vulnerable to membership inference on their training datasets. With updated pre-trained NER models from spaCy, we demonstrate two distinct membership attacks on these models. Our first attack capitalizes on unintended memorization in the NER's underlying neural network, a phenomenon NNs are known to be vulnerable to. Our second attack leverages a timing side-channel to target NER models that maintain vocabularies constructed from the training data. We show that different functional paths of words within the training dataset in contrast to words not previously seen have measurable differences in execution time. Revealing membership status of training samples has clear privacy implications, e.g., in text redaction, sensitive words or phrases to be found and removed, are at risk of being detected in the training dataset. Our experimental evaluation includes the redaction of both password and health data, presenting both security risks and privacy/regulatory issues. This is exacerbated by results that show memorization with only a single phrase. We achieved 70% AUC in our first attack on a text redaction use-case. We also show overwhelming success in the timing attack with 99.23% AUC. Finally we discuss potential mitigation approaches to realize the safe use of NER models in light of the privacy and security implications of membership inference attacks.

确保适当的标点符号和字母外壳是朝向应用复杂的自然语言处理算法的关键预处理步骤。这对于缺少标点符号和壳体的文本源，例如自动语音识别系统的原始输出。此外，简短的短信和微博的平台提供不可靠且经常错误的标点符号和套管。本调查概述了历史和最先进的技术，用于恢复标点符号和纠正单词套管。此外，突出了当前的挑战和研究方向。

We propose a unified neural network architecture and learning algorithm that can be applied to various natural language processing tasks including: part-of-speech tagging, chunking, named entity recognition, and semantic role labeling. This versatility is achieved by trying to avoid task-specific engineering and therefore disregarding a lot of prior knowledge. Instead of exploiting man-made input features carefully optimized for each task, our system learns internal representations on the basis of vast amounts of mostly unlabeled training data. This work is then used as a basis for building a freely available tagging system with good performance and minimal computational requirements.

State-of-the-art named entity recognition systems rely heavily on hand-crafted features and domain-specific knowledge in order to learn effectively from the small, supervised training corpora that are available. In this paper, we introduce two new neural architectures-one based on bidirectional LSTMs and conditional random fields, and the other that constructs and labels segments using a transition-based approach inspired by shift-reduce parsers. Our models rely on two sources of information about words: character-based word representations learned from the supervised corpus and unsupervised word representations learned from unannotated corpora. Our models obtain state-of-the-art performance in NER in four languages without resorting to any language-specific knowledge or resources such as gazetteers. 1

Natural Language Understanding has seen an increasing number of publications in the last few years, especially after robust word embeddings models became prominent, when they proved themselves able to capture and represent semantic relationships from massive amounts of data. Nevertheless, traditional models often fall short in intrinsic issues of linguistics, such as polysemy and homonymy. Any expert system that makes use of natural language in its core, can be affected by a weak semantic representation of text, resulting in inaccurate outcomes based on poor decisions. To mitigate such issues, we propose a novel approach called Most Suitable Sense Annotation (MSSA), that disambiguates and annotates each word by its specific sense, considering the semantic effects of its context. Our approach brings three main contributions to the semantic representation scenario: (i) an unsupervised technique that disambiguates and annotates words by their senses, (ii) a multi-sense embeddings model that can be extended to any traditional word embeddings algorithm, and (iii) a recurrent methodology that allows our models to be re-used and their representations refined. We test our approach on six different benchmarks for the word similarity task, showing that our approach can produce state-of-the-art results and outperforms several more complex state-of-the-art systems.

The relationship between words in a sentence often tells us more about the underlying semantic content of a document than its actual words, individually. In this work, we propose two novel algorithms, called Flexible Lexical Chain II and Fixed Lexical Chain II. These algorithms combine the semantic relations derived from lexical chains, prior knowledge from lexical databases, and the robustness of the distributional hypothesis in word embeddings as building blocks forming a single system. In short, our approach has three main contributions: (i) a set of techniques that fully integrate word embeddings and lexical chains; (ii) a more robust semantic representation that considers the latent relation between words in a document; and (iii) lightweight word embeddings models that can be extended to any natural language task. We intend to assess the knowledge of pre-trained models to evaluate their robustness in the document classification task. The proposed techniques are tested against seven word embeddings algorithms using five different machine learning classifiers over six scenarios in the document classification task. Our results show the integration between lexical chains and word embeddings representations sustain state-of-the-art results, even against more complex systems.

命名实体识别是一项信息提取任务，可作为其他自然语言处理任务的预处理步骤，例如机器翻译，信息检索和问题答案。命名实体识别能够识别专有名称以及开放域文本中的时间和数字表达式。对于诸如阿拉伯语，阿姆哈拉语和希伯来语之类的闪族语言，由于这些语言的结构严重变化，指定的实体识别任务更具挑战性。在本文中，我们提出了一个基于双向长期记忆的Amharic命名实体识别系统，并带有条件随机字段层。我们注释了一种新的Amharic命名实体识别数据集（8,070个句子，具有182,691个令牌），并将合成少数群体过度采样技术应用于我们的数据集，以减轻不平衡的分类问题。我们命名的实体识别系统的F_1得分为93％，这是Amharic命名实体识别的新最新结果。

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。

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.

Transformer language models (TLMs) are critical for most NLP tasks, but they are difficult to create for low-resource languages because of how much pretraining data they require. In this work, we investigate two techniques for training monolingual TLMs in a low-resource setting: greatly reducing TLM size, and complementing the masked language modeling objective with two linguistically rich supervised tasks (part-of-speech tagging and dependency parsing). Results from 7 diverse languages indicate that our model, MicroBERT, is able to produce marked improvements in downstream task evaluations relative to a typical monolingual TLM pretraining approach. Specifically, we find that monolingual MicroBERT models achieve gains of up to 18% for parser LAS and 11% for NER F1 compared to a multilingual baseline, mBERT, while having less than 1% of its parameter count. We conclude reducing TLM parameter count and using labeled data for pretraining low-resource TLMs can yield large quality benefits and in some cases produce models that outperform multilingual approaches.

Wikidata是一个经常更新，社区驱动和多语言知识图形。因此，Wikidata是实体联系的一个有吸引力的基础，这是最近发表论文的增加显而易见的。该调查侧重于四个主题：（1）存在哪些Wikidata实体链接数据集，它们是多么广泛使用，它们是如何构建的？ （2）对实体联系数据集的设计进行Wikidata的特点，如果是的话，怎么样？ （3）当前实体链接方法如何利用Wikidata的特定特征？ （4）现有实体链接方法未开发哪种Wikidata特征？本次调查显示，当前的Wikidata特定实体链接数据集在其他知识图表中的方案中的注释方案中没有不同。因此，没有提升多语言和时间依赖数据集的可能性，是自然适合维基帽的数据集。此外，我们表明大多数实体链接方法使用Wikidata以与任何其他知识图相同的方式，因为任何其他知识图都缺少了利用Wikidata特定特征来提高质量的机会。几乎所有方法都使用标签等特定属性，有时是描述，而是忽略超关系结构等特征。因此，例如，通过包括超关系图嵌入或类型信息，仍有改进的余地。许多方法还包括来自维基百科的信息，这些信息很容易与Wikidata组合并提供有价值的文本信息，Wikidata缺乏。

本教程展示了工作流程，将文本数据纳入精算分类和回归任务。主要重点是采用基于变压器模型的方法。平均长度为400个单词的车祸描述的数据集，英语和德语可用，以及具有简短财产保险索赔的数据集用来证明这些技术。案例研究应对与多语言环境和长输入序列有关的挑战。他们还展示了解释模型输出，评估和改善模型性能的方法，通过将模型调整到应用程序领域或特定预测任务。最后，该教程提供了在没有或仅有少数标记数据的情况下处理分类任务的实用方法。通过使用最少的预处理和微调的现成自然语言处理（NLP）模型的语言理解技能（NLP）模型实现的结果清楚地证明了用于实际应用的转移学习能力。

链接的开放数据实践导致了过去十年中网络上结构化数据的显着增长。这样的结构化数据以机器可读的方式描述了现实世界实体，并为自然语言处理领域的研究创造了前所未有的机会。但是，缺乏有关如何使用此类数据，哪种任务以及它们在多大程度上对这些任务有用的研究。这项工作着重于电子商务领域，以探索利用此类结构化数据来创建可能用于产品分类和链接的语言资源的方法。我们以RDF N四分之一的形式处理数十亿个结构化数据点，以创建数百万个与产品相关的语料库单词，后来以三种不同的方式用于创建语言资源：培训单词嵌入模型，继续预训练类似于Bert的语言模型和训练机器翻译模型，这些模型被用作生成产品相关的关键字的代理。我们对大量基准测试的评估表明，嵌入单词是提高这两个任务准确性的最可靠和一致的方法（在某些数据集中，宏观 - 平均F1中最高6.9个百分点）。但是，其他两种方法并不那么有用。我们的分析表明，这可能是由于许多原因，包括结构化数据中的偏置域表示以及缺乏词汇覆盖范围。我们分享我们的数据集，并讨论如何将我们所学到的经验教训朝着这一方向介绍未来的研究。

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).

News articles both shape and reflect public opinion across the political spectrum. Analyzing them for social bias can thus provide valuable insights, such as prevailing stereotypes in society and the media, which are often adopted by NLP models trained on respective data. Recent work has relied on word embedding bias measures, such as WEAT. However, several representation issues of embeddings can harm the measures' accuracy, including low-resource settings and token frequency differences. In this work, we study what kind of embedding algorithm serves best to accurately measure types of social bias known to exist in US online news articles. To cover the whole spectrum of political bias in the US, we collect 500k articles and review psychology literature with respect to expected social bias. We then quantify social bias using WEAT along with embedding algorithms that account for the aforementioned issues. We compare how models trained with the algorithms on news articles represent the expected social bias. Our results suggest that the standard way to quantify bias does not align well with knowledge from psychology. While the proposed algorithms reduce the~gap, they still do not fully match the literature.

我们在佩恩 - 赫尔辛基解析的早期现代英语（PPCEME）中的第一个解析结果，是一个190万字的TreeBank，这是句法变化研究的重要资源。我们描述了PPCEME的关键特征，使其成为解析的挑战，包括比Penn TreeBank中更大且更多样化的功能标签。我们使用伯克利神经解析器的修改版本为此语料库提出了结果，以及Gabbard等人的功能标签恢复的方法（2006）。尽管其简单性，这种方法令人惊讶地令人惊讶地令人惊讶的是，建议可以以足够的准确度恢复原始结构，以支持语言应用（例如，寻找涉及的句法结构）。然而，对于函数标签的子集（例如，指示直接演讲的标签），需要额外的工作，我们讨论了这种方法的一些进一步限制。由此产生的解析器将用于在网上解析早期英语书籍，一个11亿字形的语料库，其实用性对于句法变化的效用将大大增加，加入准确的解析树。

令牌化是预用语言模型（PLMS）的基础。用于中文PLMS的现有销量化方法通常将每个角色视为不可分割的令牌。然而，它们忽略了中文写字系统的独特特征，其中附加语言信息在字符级别下方，即在子字符级别。要利用此类信息，我们提出了子字符（Sub Const for Short）标记。具体地，我们首先通过基于其字形或发音将每个汉字转换为短序列来编码输入文本，然后根据具有子字标记化的编码文本构造词汇表。实验结果表明，Sub Colar标记与现有标记均具有两个主要优点：1）它们可以将输入牌销料到更短的序列中，从而提高计算效率。 2）基于发音的Sub Col.Tokenizers可以将中文同音铭器编码为相同的音译序列并产生相同的标记输出，因此对所有同音声音拼写的强大。与此同时，使用Sub Colar标记培训的模型竞争地执行下游任务。我们在https://github.com/thunlp/subchartoken中发布我们的代码，以促进未来的工作。

虽然有几种可用于匈牙利语的源语言处理管道，但它们都不满足当今NLP应用程序的要求。语言处理管道应由接近最先进的lemmatization，形态学分析，实体识别和单词嵌入。工业文本处理应用程序必须满足非功能性的软件质量要求，更重要的是，支持多种语言的框架越来越受青睐。本文介绍了哈普西，匈牙利匈牙利语言处理管道。呈现的工具为最重要的基本语言分析任务提供组件。它是开源，可在许可证下提供。我们的系统建立在Spacy的NLP组件之上，这意味着它快速，具有丰富的NLP应用程序和扩展生态系统，具有广泛的文档和众所周知的API。除了底层模型的概述外，我们还对共同的基准数据集呈现严格的评估。我们的实验证实，母鹿在所有子组织中具有高精度，同时保持资源有效的预测能力。

Contextualized representation models such as ELMo (Peters et al., 2018a) and BERT (Devlin et al., 2018) have recently achieved state-of-the-art results on a diverse array of downstream NLP tasks. Building on recent token-level probing work, we introduce a novel edge probing task design and construct a broad suite of sub-sentence tasks derived from the traditional structured NLP pipeline. We probe word-level contextual representations from four recent models and investigate how they encode sentence structure across a range of syntactic, semantic, local, and long-range phenomena. We find that existing models trained on language modeling and translation produce strong representations for syntactic phenomena, but only offer comparably small improvements on semantic tasks over a non-contextual baseline.