命名实体识别（ner）是从文本中提取特定类型的命名实体的任务。当前的NER模型往往依赖于人类注释的数据集，要求在目标领域和实体上广泛参与专业知识。这项工作介绍了一个询问生成的方法，它通过询问反映实体类型的需求的简单自然语言问题来自动生成NER数据集（例如，哪种疾病？）到开放式域问题应答系统。不使用任何域中资源（即，培训句子，标签或域名词典），我们的模型在我们生成的数据集上仅培训了，这在很大程度上超过了四个不同域的六个基准测试的弱势监督模型。令人惊讶的是，在NCBI疾病中，我们的模型达到75.5 F1得分，甚至优于以前的最佳弱监督模型4.1 F1得分，它利用域专家提供的丰富的域名词典。制定具有自然语言的NER的需求，也允许我们为诸如奖项等细粒度实体类型构建NER模型，其中我们的模型甚至优于完全监督模型。在三个少量的NER基准测试中，我们的模型实现了新的最先进的性能。

We present, Naamapadam, the largest publicly available Named Entity Recognition (NER) dataset for the 11 major Indian languages from two language families. In each language, it contains more than 400k sentences annotated with a total of at least 100k entities from three standard entity categories (Person, Location and Organization) for 9 out of the 11 languages. The training dataset has been automatically created from the Samanantar parallel corpus by projecting automatically tagged entities from an English sentence to the corresponding Indian language sentence. We also create manually annotated testsets for 8 languages containing approximately 1000 sentences per language. We demonstrate the utility of the obtained dataset on existing testsets and the Naamapadam-test data for 8 Indic languages. We also release IndicNER, a multilingual mBERT model fine-tuned on the Naamapadam training set. IndicNER achieves the best F1 on the Naamapadam-test set compared to an mBERT model fine-tuned on existing datasets. IndicNER achieves an F1 score of more than 80 for 7 out of 11 Indic languages. The dataset and models are available under open-source licenses at https://ai4bharat.iitm.ac.in/naamapadam.

The strong few-shot in-context learning capability of large pre-trained language models (PLMs) such as GPT-3 is highly appealing for application domains such as biomedicine, which feature high and diverse demands of language technologies but also high data annotation costs. In this paper, we present the first systematic and comprehensive study to compare the few-shot performance of GPT-3 in-context learning with fine-tuning smaller (i.e., BERT-sized) PLMs on two highly representative biomedical information extraction tasks, named entity recognition and relation extraction. We follow the true few-shot setting to avoid overestimating models' few-shot performance by model selection over a large validation set. We also optimize GPT-3's performance with known techniques such as contextual calibration and dynamic in-context example retrieval. However, our results show that GPT-3 still significantly underperforms compared to simply fine-tuning a smaller PLM. In addition, GPT-3 in-context learning also yields smaller gains in accuracy when more training data becomes available. Our in-depth analyses further reveal issues of the in-context learning setting that may be detrimental to information extraction tasks in general. Given the high cost of experimenting with GPT-3, we hope our study provides guidance for biomedical researchers and practitioners towards more promising directions such as fine-tuning small PLMs.

当大型训练数据集不可用于低资源域时，命名实体识别（NER）模型通常表现不佳。最近，预先训练大规模语言模型已成为应对数据稀缺问题的有希望的方向。然而，语言建模和ner任务之间的潜在差异可能会限制模型的性能，并且由于收集的网数据集通常很小或大而是低质量，因此已经研究了NER任务的预训练。在本文中，我们构建了一个具有相对高质量的大规模核心语料库，我们基于创建的数据集预先列车。实验结果表明，我们的预训练模型可以显着优于八大域的低资源场景中的百合形和其他强基线。此外，实体表示的可视化进一步指示Ner-BERT用于对各种实体进行分类的有效性。

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。

在科学研究中，该方法是解决科学问题和关键研究对象的必不可少手段。随着科学的发展，正在提出，修改和使用许多科学方法。作者在抽象和身体文本中描述了该方法的详细信息，并且反映该方法名称的学术文献中的关键实体称为方法实体。在大量的学术文献中探索各种方法实体有助于学者了解现有方法，为研究任务选择适当的方法并提出新方法。此外，方法实体的演变可以揭示纪律的发展并促进知识发现。因此，本文对方法论和经验作品进行了系统的综述，重点是从全文学术文献中提取方法实体，并努力使用这些提取的方法实体来建立知识服务。首先提出了本综述涉及的关键概念的定义。基于这些定义，我们系统地审查了提取和评估方法实体的方法和指标，重点是每种方法的利弊。我们还调查了如何使用提取的方法实体来构建新应用程序。最后，讨论了现有作品的限制以及潜在的下一步。

非结构化的文本中存在大量的位置信息，例如社交媒体帖子，新闻报道，科学文章，网页，旅行博客和历史档案。地理学是指识别文本中的位置参考并识别其地理空间表示的过程。虽然地理标准可以使许多领域受益，但仍缺少特定应用程序的摘要。此外，缺乏对位置参考识别方法的现有方法的全面审查和比较，这是地理验证的第一个和核心步骤。为了填补这些研究空白，这篇综述首先总结了七个典型的地理应用程序域：地理信息检索，灾难管理，疾病监视，交通管理，空间人文，旅游管理和犯罪管理。然后，我们通过将这些方法分类为四个组，以基于规则的基于规则，基于统计学学习的基于统计学学习和混合方法将这些方法分类为四个组，从而回顾了现有的方法参考识别方法。接下来，我们彻底评估了27种最广泛使用的方法的正确性和计算效率，该方法基于26个公共数据集，其中包含不同类型的文本（例如，社交媒体帖子和新闻报道），包含39,736个位置参考。这项彻底评估的结果可以帮助未来的方法论发展以获取位置参考识别，并可以根据应用需求指导选择适当方法的选择。

A long-running goal of the clinical NLP community is the extraction of important variables trapped in clinical notes. However, roadblocks have included dataset shift from the general domain and a lack of public clinical corpora and annotations. In this work, we show that large language models, such as InstructGPT, perform well at zero- and few-shot information extraction from clinical text despite not being trained specifically for the clinical domain. Whereas text classification and generation performance have already been studied extensively in such models, here we additionally demonstrate how to leverage them to tackle a diverse set of NLP tasks which require more structured outputs, including span identification, token-level sequence classification, and relation extraction. Further, due to the dearth of available data to evaluate these systems, we introduce new datasets for benchmarking few-shot clinical information extraction based on a manual re-annotation of the CASI dataset for new tasks. On the clinical extraction tasks we studied, the GPT-3 systems significantly outperform existing zero- and few-shot baselines.

We present Pre-trained Machine Reader (PMR), a novel method to retrofit Pre-trained Language Models (PLMs) into Machine Reading Comprehension (MRC) models without acquiring labeled data. PMR is capable of resolving the discrepancy between model pre-training and downstream fine-tuning of existing PLMs, and provides a unified solver for tackling various extraction tasks. To achieve this, we construct a large volume of general-purpose and high-quality MRC-style training data with the help of Wikipedia hyperlinks and design a Wiki Anchor Extraction task to guide the MRC-style pre-training process. Although conceptually simple, PMR is particularly effective in solving extraction tasks including Extractive Question Answering and Named Entity Recognition, where it shows tremendous improvements over previous approaches especially under low-resource settings. Moreover, viewing sequence classification task as a special case of extraction task in our MRC formulation, PMR is even capable to extract high-quality rationales to explain the classification process, providing more explainability of the predictions.

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。

In this work, we introduce IndicXTREME, a benchmark consisting of nine diverse tasks covering 18 languages from the Indic sub-continent belonging to four different families. Across languages and tasks, IndicXTREME contains a total of 103 evaluation sets, of which 51 are new contributions to the literature. To maintain high quality, we only use human annotators to curate or translate\footnote{for IndicXParaphrase, where an automatic translation system is used, a second human verification and correction step is done.} our datasets. To the best of our knowledge, this is the first effort toward creating a standard benchmark for Indic languages that aims to test the zero-shot capabilities of pretrained language models. We also release IndicCorp v2, an updated and much larger version of IndicCorp that contains 20.9 billion tokens in 24 languages. We pretrain IndicBERT v2 on IndicCorp v2 and evaluate it on IndicXTREME to show that it outperforms existing multilingual language models such as XLM-R and MuRIL.

生物医学研究正在以这种指数速度增长，科学家，研究人员和从业者不再能够应对该领域发表的文献的数量。文献中提出的知识需要以这种方式系统化，可以轻松找到声明和假设，访问和验证。知识图可以为文献提供这样的语义知识表示框架。然而，为了构建知识图形，有必要以生物医学实体之间的关系形式提取知识并使两个实体和关系类型进行正常化。在本文中，我们展示并比较了少数基于规则和基于机器学习的（天真的贝叶斯，随机森林作为传统机器学习方法和T5基础的示例，作为现代深层学习的示例）可扩展关系从生物医学中提取的方法集成到知识图中的文献。我们研究了如何为不平衡和相当小的数据集进行弹性，显示T5模型，由于其在大型C4数据集以及不平衡数据上进行预培训，因此T5模型处理得好的小型数据集。最佳执行模型是T5模型在平衡数据上进行微调，报告F1分数为0.88。

Pre-trained Language Models (PLMs) have been applied in NLP tasks and achieve promising results. Nevertheless, the fine-tuning procedure needs labeled data of the target domain, making it difficult to learn in low-resource and non-trivial labeled scenarios. To address these challenges, we propose Prompt-based Text Entailment (PTE) for low-resource named entity recognition, which better leverages knowledge in the PLMs. We first reformulate named entity recognition as the text entailment task. The original sentence with entity type-specific prompts is fed into PLMs to get entailment scores for each candidate. The entity type with the top score is then selected as final label. Then, we inject tagging labels into prompts and treat words as basic units instead of n-gram spans to reduce time complexity in generating candidates by n-grams enumeration. Experimental results demonstrate that the proposed method PTE achieves competitive performance on the CoNLL03 dataset, and better than fine-tuned counterparts on the MIT Movie and Few-NERD dataset in low-resource settings.

Two key obstacles in biomedical relation extraction (RE) are the scarcity of annotations and the prevalence of instances without explicitly pre-defined labels due to low annotation coverage. Existing approaches, which treat biomedical RE as a multi-class classification task, often result in poor generalization in low-resource settings and do not have the ability to make selective prediction on unknown cases but give a guess from seen relations, hindering the applicability of those approaches. We present NBR, which converts biomedical RE as natural language inference formulation through indirect supervision. By converting relations to natural language hypotheses, NBR is capable of exploiting semantic cues to alleviate annotation scarcity. By incorporating a ranking-based loss that implicitly calibrates abstinent instances, NBR learns a clearer decision boundary and is instructed to abstain on uncertain instances. Extensive experiments on three widely-used biomedical RE benchmarks, namely ChemProt, DDI and GAD, verify the effectiveness of NBR in both full-set and low-resource regimes. Our analysis demonstrates that indirect supervision benefits biomedical RE even when a domain gap exists, and combining NLI knowledge with biomedical knowledge leads to the best performance gains.

Translating training data into many languages has emerged as a practical solution for improving cross-lingual transfer. For tasks that involve span-level annotations, such as information extraction or question answering, an additional label projection step is required to map annotated spans onto the translated texts. Recently, a few efforts have utilized a simple mark-then-translate method to jointly perform translation and projection by inserting special markers around the labeled spans in the original sentence. However, as far as we are aware, no empirical analysis has been conducted on how this approach compares to traditional annotation projection based on word alignment. In this paper, we present an extensive empirical study across 42 languages and three tasks (QA, NER, and Event Extraction) to evaluate the effectiveness and limitations of both methods, filling an important gap in the literature. Experimental results show that our optimized version of mark-then-translate, which we call EasyProject, is easily applied to many languages and works surprisingly well, outperforming the more complex word alignment-based methods. We analyze several key factors that affect end-task performance, and show EasyProject works well because it can accurately preserve label span boundaries after translation. We will publicly release all our code and data.

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.

基于强大的预训练语言模型（PLM）的密集检索方法（DR）方法取得了重大进步，并已成为现代开放域问答系统的关键组成部分。但是，他们需要大量的手动注释才能进行竞争性，这是不可行的。为了解决这个问题，越来越多的研究作品最近着重于在低资源场景下改善DR绩效。这些作品在培训所需的资源和采用各种技术的资源方面有所不同。了解这种差异对于在特定的低资源场景下选择正确的技术至关重要。为了促进这种理解，我们提供了针对低资源DR的主流技术的彻底结构化概述。根据他们所需的资源，我们将技术分为三个主要类别：（1）仅需要文档； （2）需要文件和问题； （3）需要文档和提问对。对于每种技术，我们都会介绍其一般形式算法，突出显示开放的问题和利弊。概述了有希望的方向以供将来的研究。

我们提出了多语言数据集的Multiconer，用于命名实体识别，涵盖11种语言的3个域（Wiki句子，问题和搜索查询），以及多语言和代码混合子集。该数据集旨在代表NER中的当代挑战，包括低文字方案（简短和未添加的文本），句法复杂的实体（例如电影标题）和长尾实体分布。使用基于启发式的句子采样，模板提取和插槽以及机器翻译等技术，从公共资源中汇编了26M令牌数据集。我们在数据集上应用了两个NER模型：一个基线XLM-Roberta模型和一个最先进的Gemnet模型，该模型利用了Gazetteers。基线实现了中等的性能（Macro-F1 = 54％），突出了我们数据的难度。 Gemnet使用Gazetteers，显着改善（Macro-F1 =+30％的平均改善）。甚至对于大型预训练的语言模型，多功能人也会构成挑战，我们认为它可以帮助进一步研究建立强大的NER系统。 Multiconer可在https://registry.opendata.aws/multiconer/上公开获取，我们希望该资源将有助于推进NER各个方面的研究。

作为人类认知的重要组成部分，造成效果关系频繁出现在文本中，从文本策划原因关系有助于建立预测任务的因果网络。现有的因果关系提取技术包括基于知识的，统计机器学习（ML）和基于深度学习的方法。每种方法都具有其优点和缺点。例如，基于知识的方法是可以理解的，但需要广泛的手动域知识并具有较差的跨域适用性。由于自然语言处理（NLP）工具包，统计机器学习方法更加自动化。但是，功能工程是劳动密集型的，工具包可能导致错误传播。在过去的几年里，由于其强大的代表学习能力和计算资源的快速增加，深入学习技术吸引了NLP研究人员的大量关注。它们的局限包括高计算成本和缺乏足够的注释培训数据。在本文中，我们对因果关系提取进行了综合调查。我们最初介绍了因果关系提取中存在的主要形式：显式的内部管制因果关系，隐含因果关系和间情态因果关系。接下来，我们列出了代理关系提取的基准数据集和建模评估方法。然后，我们介绍了三种技术的结构化概述了与他们的代表系统。最后，我们突出了潜在的方向存在现有的开放挑战。

We present TriviaQA, a challenging reading comprehension dataset containing over 650K question-answer-evidence triples. TriviaQA includes 95K questionanswer pairs authored by trivia enthusiasts and independently gathered evidence documents, six per question on average, that provide high quality distant supervision for answering the questions. We show that, in comparison to other recently introduced large-scale datasets, TriviaQA (1) has relatively complex, compositional questions, (2) has considerable syntactic and lexical variability between questions and corresponding answer-evidence sentences, and (3) requires more cross sentence reasoning to find answers. We also present two baseline algorithms: a featurebased classifier and a state-of-the-art neural network, that performs well on SQuAD reading comprehension. Neither approach comes close to human performance (23% and 40% vs. 80%), suggesting that Trivi-aQA is a challenging testbed that is worth significant future study. 1