Inductive transfer learning has greatly impacted computer vision, but existing approaches in NLP still require task-specific modifications and training from scratch. We propose Universal Language Model Fine-tuning (ULMFiT), an effective transfer learning method that can be applied to any task in NLP, and introduce techniques that are key for fine-tuning a language model. Our method significantly outperforms the state-of-the-art on six text classification tasks, reducing the error by 18-24% on the majority of datasets. Furthermore, with only 100 labeled examples, it matches the performance of training from scratch on 100× more data. We opensource our pretrained models and code 1 .

Language model pre-training has proven to be useful in learning universal language representations. As a state-of-the-art language model pre-training model, BERT (Bidirectional Encoder Representations from Transformers) has achieved amazing results in many language understanding tasks. In this paper, we conduct exhaustive experiments to investigate different fine-tuning methods of BERT on text classification task and provide a general solution for BERT fine-tuning. Finally, the proposed solution obtains new state-of-the-art results on eight widely-studied text classification datasets. 1

GPT-2和BERT展示了在各种自然语言处理任务上使用预训练的语言模型（LMS）的有效性。但是，在应用于资源丰富的任务时，LM微调通常会遭受灾难性的遗忘。在这项工作中，我们引入了一个协同的培训框架（CTNMT），该框架是将预训练的LMS集成到神经机器翻译（NMT）的关键。我们提出的CTNMT包括三种技术：a）渐近蒸馏，以确保NMT模型可以保留先前的预训练知识； b）动态的开关门，以避免灾难性忘记预训练的知识； c）根据计划的政策调整学习步伐的策略。我们在机器翻译中的实验表明，WMT14英语 - 德语对的CTNMT获得了最高3个BLEU得分，甚至超过了先前的最先进的预培训辅助NMT NMT的NMT。尽管对于大型WMT14英语法国任务，有400万句话，但我们的基本模型仍然可以显着改善最先进的变压器大型模型，超过1个BLEU得分。代码和模型可以从https://github.com/bytedance/neurst/tree/Master/Master/examples/ctnmt下载。

We introduce a new type of deep contextualized word representation that models both (1) complex characteristics of word use (e.g., syntax and semantics), and (2) how these uses vary across linguistic contexts (i.e., to model polysemy). Our word vectors are learned functions of the internal states of a deep bidirectional language model (biLM), which is pretrained on a large text corpus. We show that these representations can be easily added to existing models and significantly improve the state of the art across six challenging NLP problems, including question answering, textual entailment and sentiment analysis. We also present an analysis showing that exposing the deep internals of the pre-trained network is crucial, allowing downstream models to mix different types of semi-supervision signals.

转移学习已通过深度审慎的语言模型广泛用于自然语言处理，例如来自变形金刚和通用句子编码器的双向编码器表示。尽管取得了巨大的成功，但语言模型应用于小型数据集时会过多地适合，并且很容易忘记与分类器进行微调时。为了解决这个忘记将深入的语言模型从一个域转移到另一个领域的问题，现有的努力探索了微调方法，以减少忘记。我们建议DeepeMotex是一种有效的顺序转移学习方法，以检测文本中的情绪。为了避免忘记问题，通过从Twitter收集的大量情绪标记的数据来仪器进行微调步骤。我们使用策划的Twitter数据集和基准数据集进行了一项实验研究。 DeepeMotex模型在测试数据集上实现多级情绪分类的精度超过91％。我们评估了微调DeepeMotex模型在分类Emoint和刺激基准数据集中的情绪时的性能。这些模型在基准数据集中的73％的实例中正确分类了情绪。所提出的DeepeMotex-Bert模型优于BI-LSTM在基准数据集上的BI-LSTM增长23％。我们还研究了微调数据集的大小对模型准确性的影响。我们的评估结果表明，通过大量情绪标记的数据进行微调提高了最终目标任务模型的鲁棒性和有效性。

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).

We present two approaches to use unlabeled data to improve Sequence Learning with recurrent networks. The first approach is to predict what comes next in a sequence, which is a language model in NLP. The second approach is to use a sequence autoencoder, which reads the input sequence into a vector and predicts the input sequence again. These two algorithms can be used as a "pretraining" algorithm for a later supervised sequence learning algorithm. In other words, the parameters obtained from the pretraining step can then be used as a starting point for other supervised training models. In our experiments, we find that long short term memory recurrent networks after pretrained with the two approaches become more stable to train and generalize better. With pretraining, we were able to achieve strong performance in many classification tasks, such as text classification with IMDB, DBpedia or image recognition in CIFAR-10.

Fine-tuning large pre-trained models is an effective transfer mechanism in NLP. However, in the presence of many downstream tasks, fine-tuning is parameter inefficient: an entire new model is required for every task. As an alternative, we propose transfer with adapter modules. Adapter modules yield a compact and extensible model; they add only a few trainable parameters per task, and new tasks can be added without revisiting previous ones. The parameters of the original network remain fixed, yielding a high degree of parameter sharing. To demonstrate adapter's effectiveness, we transfer the recently proposed BERT Transformer model to 26 diverse text classification tasks, including the GLUE benchmark. Adapters attain near state-of-the-art performance, whilst adding only a few parameters per task. On GLUE, we attain within 0.4% of the performance of full fine-tuning, adding only 3.6% parameters per task. By contrast, fine-tuning trains 100% of the parameters per task.

Language models pretrained on text from a wide variety of sources form the foundation of today's NLP. In light of the success of these broad-coverage models, we investigate whether it is still helpful to tailor a pretrained model to the domain of a target task. We present a study across four domains (biomedical and computer science publications, news, and reviews) and eight classification tasks, showing that a second phase of pretraining indomain (domain-adaptive pretraining) leads to performance gains, under both high-and low-resource settings. Moreover, adapting to the task's unlabeled data (task-adaptive pretraining) improves performance even after domain-adaptive pretraining. Finally, we show that adapting to a task corpus augmented using simple data selection strategies is an effective alternative, especially when resources for domain-adaptive pretraining might be unavailable. Overall, we consistently find that multiphase adaptive pretraining offers large gains in task performance.

多语言语言模型（\ mllms），如mbert，xlm，xlm-r，\ textit {etc。}已成为一种可行的选择，使预先估计到大量语言的力量。鉴于他们的成功在零射击转移学习中，在（i）建立更大的\ mllms〜覆盖了大量语言（ii）创建覆盖更广泛的任务和语言来评估的详尽工作基准mllms〜（iii）分析单音零点，零拍摄交叉和双语任务（iv）对Monolingual的性能，了解\ mllms〜（v）增强（通常）学习的通用语言模式（如果有的话）有限的容量\ mllms〜以提高他们在已见甚至看不见语言的表现。在这项调查中，我们审查了现有的文学，涵盖了上述与\ MLLMS有关的广泛研究领域。根据我们的调查，我们建议您有一些未来的研究方向。

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.

大型语言模型在各种任务上显示出令人印象深刻的几次结果。但是，当知识是此类结果的关键时，就像问题回答和事实检查之类的任务一样，似乎需要存储知识的大量参数计数。众所周知，检索增强模型可以在不需要多个参数的情况下在知识密集的任务上表现出色，但是目前尚不清楚它们是否在几个弹药设置中工作。在这项工作中，我们介绍了地图集，这是一个经过精心设计和预先训练的增强语言模型，能够通过很少的培训示例学习知识密集型任务。我们对包括MMLU，苏格兰短裙和归类等各种任务进行评估，并研究文档索引内容的影响，表明它可以很容易地进行更新。值得注意的是，在自然问题上仅使用64个示例在自然问题上达到超过42 \％的准确性，尽管参数少了50倍，但比540B参数模型的表现优于540b参数模型。

This work introduces a new multi-task, parameter-efficient language model (LM) tuning method that learns to transfer knowledge across different tasks via a mixture of soft prompts-small prefix embedding vectors pre-trained for different tasks. Our method, called ATTEMPT (ATTEntional Mixtures of Prompt Tuning), obtains source prompts as encodings of large-scale source tasks into a small number of parameters and trains an attention module to interpolate the source prompts and a newly initialized target prompt for every instance in the target task. During training, only the target task prompt and the attention weights, which are shared between tasks in multi-task training, are updated, while the original LM and source prompts are intact. ATTEMPT is highly parameter-efficient (e.g., updates 2,300 times fewer parameters than full fine-tuning) while achieving high task performance using knowledge from high-resource tasks. Moreover, it is modular using pre-trained soft prompts, and can flexibly add or remove source prompts for effective knowledge transfer. Our experimental results across 21 diverse NLP datasets show that ATTEMPT significantly outperforms prompt tuning and outperforms or matches fully fine-tuned or other parameter-efficient tuning approaches that use over ten times more parameters. Finally, ATTEMPT outperforms previous work in few-shot learning settings.

非结构化数据，尤其是文本，在各个领域继续迅速增长。特别是，在金融领域，有大量累积的非结构化财务数据，例如公司定期向监管机构提交的文本披露文件，例如证券和交易委员会（SEC）。这些文档通常很长，并且倾向于包含有关公司绩效的宝贵信息。因此，从这些长文本文档中学习预测模型是非常兴趣的，尤其是用于预测数值关键绩效指标（KPI）。尽管在训练有素的语言模型（LMS）中取得了长足的进步，这些模型从大量的文本数据中学习，但他们仍然在有效的长期文档表示方面挣扎。我们的工作满足了这种批判性需求，即如何开发更好的模型来从长文本文档中提取有用的信息，并学习有效的功能，这些功能可以利用软件财务和风险信息来进行文本回归（预测）任务。在本文中，我们提出并实施了一个深度学习框架，该框架将长文档分为大块，并利用预先训练的LMS处理和将块汇总为矢量表示，然后进行自我关注以提取有价值的文档级特征。我们根据美国银行的10-K公共披露报告以及美国公司提交的另一个报告数据集评估了模型。总体而言，我们的框架优于文本建模的强大基线方法以及仅使用数值数据的基线回归模型。我们的工作提供了更好的见解，即如何利用预先训练的域特异性和微调的长输入LMS来表示长文档可以提高文本数据的表示质量，从而有助于改善预测分析。

大型的语言模型（PRELMS）正在彻底改变所有基准的自然语言处理。但是，它们的巨大尺寸对于小型实验室或移动设备上的部署而言是过分的。修剪和蒸馏等方法可减少模型尺寸，但通常保留相同的模型体系结构。相反，我们探索了蒸馏预告片中的更有效的架构，单词的持续乘法（CMOW），该构造将每个单词嵌入为矩阵，并使用矩阵乘法来编码序列。我们扩展了CMOW体系结构及其CMOW/CBOW-HYBRID变体，具有双向组件，以提供更具表现力的功能，在预绘制期间进行一般（任务无义的）蒸馏的单次表示，并提供了两种序列编码方案，可促进下游任务。句子对，例如句子相似性和自然语言推断。我们的基于矩阵的双向CMOW/CBOW-HYBRID模型在问题相似性和识别文本范围内的Distilbert具有竞争力，但仅使用参数数量的一半，并且在推理速度方面快三倍。除了情感分析任务SST-2和语言可接受性任务COLA外，我们匹配或超过ELMO的ELMO分数。但是，与以前的跨架结构蒸馏方法相比，我们证明了检测语言可接受性的分数增加了一倍。这表明基于基质的嵌入可用于将大型预赛提炼成竞争模型，并激励朝这个方向进行进一步的研究。

深语模型在NLP域中取得了显着的成功。培养深层语言模型的标准方法是从大型未标记的语料库中雇用无监督的学习。但是，这种大型公司仅适用于广泛采用和高资源语言和域名。本研究提出了第一款深语型号DPRK-BERT为朝鲜语言。我们通过编制朝鲜语言的第一个未标记的语料库和微调预先存在的ROK语言模型来实现这一目标。我们将所提出的模型与现有方法进行比较，并显示两个DPRK数据集的显着改进。我们还提供了这种模型的交叉语言版本，其在两种韩语语言中产生了更好的泛化。最后，我们提供与朝鲜语言相关的各种NLP工具，这些工具将培养未来的研究。

深层语言语言模型（LMS）如Elmo，BERT及其继任者通过预先训练单个模型来迅速缩放自然语言处理的景观，然后是任务特定的微调。此外，像XLM-R和MBERT这样的这种模型的多语言版本使得有希望的零射击交叉传输导致，可能在许多不足和资源不足的语言中实现NLP应用。由于此初步成功，预先接受的模型被用作“通用语言模型”作为不同任务，域和语言的起点。这项工作通过识别通用模型应该能够扩展的七个维度来探讨“普遍性”的概念，即同样良好或相当良好地执行，在不同的环境中有用。我们概述了当前支持这些维度的模型性能的当前理论和经验结果，以及可能有助于解决其当前限制的扩展。通过这项调查，我们为理解大规模上下文语言模型的能力和限制奠定了基础，并帮助辨别研究差距和未来工作的方向，使这些LMS包含多样化和公平的应用，用户和语言现象。

Recent studies have proposed a unified user modeling framework that leverages user behavior data from various applications. Most benefit from utilizing users' behavior sequences as plain texts, representing rich information in any domain or system without losing generality. Hence, a question arises: Can language modeling for user history corpus help improve recommender systems? While its versatile usability has been widely investigated in many domains, its applications to recommender systems still remain underexplored. We show that language modeling applied directly to task-specific user histories achieves excellent results on diverse recommendation tasks. Also, leveraging additional task-agnostic user histories delivers significant performance benefits. We further demonstrate that our approach can provide promising transfer learning capabilities for a broad spectrum of real-world recommender systems, even on unseen domains and services.

Semi-supervised learning lately has shown much promise in improving deep learning models when labeled data is scarce. Common among recent approaches is the use of consistency training on a large amount of unlabeled data to constrain model predictions to be invariant to input noise. In this work, we present a new perspective on how to effectively noise unlabeled examples and argue that the quality of noising, specifically those produced by advanced data augmentation methods, plays a crucial role in semi-supervised learning. By substituting simple noising operations with advanced data augmentation methods such as RandAugment and back-translation, our method brings substantial improvements across six language and three vision tasks under the same consistency training framework. On the IMDb text classification dataset, with only 20 labeled examples, our method achieves an error rate of 4.20, outperforming the state-of-the-art model trained on 25,000 labeled examples. On a standard semi-supervised learning benchmark, CIFAR-10, our method outperforms all previous approaches and achieves an error rate of 5.43 with only 250 examples. Our method also combines well with transfer learning, e.g., when finetuning from BERT, and yields improvements in high-data regime, such as ImageNet, whether when there is only 10% labeled data or when a full labeled set with 1.3M extra unlabeled examples is used. 1

长尾分布式数据的分类是一个具有挑战性的问题，它遭受了严重的班级不平衡，因此只有几个样本的尾巴阶级表现不佳。由于样本的匮乏，在将预审计的模型转移到下游任务时，在尾部类中学习对于微调尤其具有挑战性。在这项工作中，我们简单地修改了标准微调，以应对这些挑战。具体而言，我们提出了一个两阶段的微调：我们首先用类平衡的重新释放损失微调了预审计模型的最后一层，然后我们执行标准的微调。我们的修改有几个好处：（1）仅通过微调模型参数的一小部分，同时保持其余部分未触及，从而利用了预告片； （2）它允许模型学习特定任务的初始表示；重要的是（3）它可以保护学习尾巴的学习免于模型更新期间处于不利地位。我们对文本分类的两类和多级任务的合成数据集进行了广泛的实验，以及用于ADME的现实世界应用（即吸收，分布，代谢和排泄）语义标记。实验结果表明，所提出的两阶段微调既优于传统损失，又超过了微调，并且在上述数据集上进行了重新调整损失。