半监督学习(SSL)在许多应用领域中已经取得了成功,但这种成功经常涉及任务特定的未标记数据的可用性。知识蒸馏(KD)能够有效地优化紧凑的神经网络,当通过新鲜任务特定的未标记数据蒸馏昂贵的网络时,实现了最佳结果。但是,任务特定的未标记数据可能具有挑战性,特别是对于NLP。我们调查使用生成模型在合成未标记数据中的使用,并呈现一个名为“生成,注释和学习(GAL)”的简单和一般框架。语言模型(LM)用于扫描域中的未标记数据。然后,分类器用于注释这样的数据。最后,综合生成和注释的数据用于推进SSL,KD和NLP和表格任务的几次拍摄学习。为了获得强大的任务特定的LM,我们要么微调来自特定任务的输入的大LM,或者提示具有少数输入示例的大型LM,并且有条件地生成更明显的示例。它还为胶水排行榜上的6层变压器产生了一种新的最先进的。最后,使用GAL的自我训练从UCI存储库的四个表格任务上提供大的收益。
translated by 谷歌翻译
GPT-3等大型语言模型是优秀的几次学习者,允许他们通过自然文本提示来控制。最近的研究报告称,基于及时的直接分类消除了对微调的需求,但缺乏数据和推理可扩展性。本文提出了一种新的数据增强技术,利用大规模语言模型来生成来自真实样本的混合的现实文本样本。我们还建议利用语言模型预测的软标签,从大规模语言模型中有效地蒸馏知识并同时创建文本扰动。我们对各种分类任务进行数据增强实验,并显示我们的方法非常优于现有的文本增强方法。消融研究和定性分析为我们的方法提供了更多的见解。
translated by 谷歌翻译
大型预估计模型(例如GPT-3)取得了显着的性能,在训练过程中暴露于大量数据上。类似地,将如此大型模型提炼成紧凑的模型以进行有效的部署,也需要大量(标记或未标记的)培训数据。在本文中,我们提出了培训高质量紧凑型模型的教师指导培训(TGT)框架,该模型利用了预验证的生成模型获得的知识,同时避免了大量数据的需求。 TGT利用了教师获得基础数据域的良好表示的事实,该事实通常对应于比输入空间要低得多的尺寸歧管。此外,我们可以使用老师通过采样或基于梯度的方法来更有效地探索输入空间。因此,使TGT对于有限的数据或长尾设置特别有吸引力。我们正式在我们的概括范围内正式捕获了所提出的数据域探索的好处。我们发现TGT可以提高几个图像分类基准以及一系列文本分类和检索任务的准确性。
translated by 谷歌翻译
Natural Language Inference (NLI) or Recognizing Textual Entailment (RTE) aims at predicting the relation between a pair of sentences (premise and hypothesis) as entailment, contradiction or semantic independence. Although deep learning models have shown promising performance for NLI in recent years, they rely on large scale expensive human-annotated datasets. Semi-supervised learning (SSL) is a popular technique for reducing the reliance on human annotation by leveraging unlabeled data for training. However, despite its substantial success on single sentence classification tasks where the challenge in making use of unlabeled data is to assign "good enough" pseudo-labels, for NLI tasks, the nature of unlabeled data is more complex: one of the sentences in the pair (usually the hypothesis) along with the class label are missing from the data and require human annotations, which makes SSL for NLI more challenging. In this paper, we propose a novel way to incorporate unlabeled data in SSL for NLI where we use a conditional language model, BART to generate the hypotheses for the unlabeled sentences (used as premises). Our experiments show that our SSL framework successfully exploits unlabeled data and substantially improves the performance of four NLI datasets in low-resource settings. We release our code at: https://github.com/msadat3/SSL_for_NLI.
translated by 谷歌翻译
数据增强是通过转换为机器学习的人工创建数据的人工创建,是一个跨机器学习学科的研究领域。尽管它对于增加模型的概括功能很有用,但它还可以解决许多其他挑战和问题,从克服有限的培训数据到正规化目标到限制用于保护隐私的数据的数量。基于对数据扩展的目标和应用的精确描述以及现有作品的分类法,该调查涉及用于文本分类的数据增强方法,并旨在为研究人员和从业者提供简洁而全面的概述。我们将100多种方法划分为12种不同的分组,并提供最先进的参考文献来阐述哪种方法可以通过将它们相互关联,从而阐述了哪种方法。最后,提供可能构成未来工作的基础的研究观点。
translated by 谷歌翻译
State-of-the-art computer vision systems are trained to predict a fixed set of predetermined object categories. This restricted form of supervision limits their generality and usability since additional labeled data is needed to specify any other visual concept. Learning directly from raw text about images is a promising alternative which leverages a much broader source of supervision. We demonstrate that the simple pre-training task of predicting which caption goes with which image is an efficient and scalable way to learn SOTA image representations from scratch on a dataset of 400 million (image, text) pairs collected from the internet. After pre-training, natural language is used to reference learned visual concepts (or describe new ones) enabling zero-shot transfer of the model to downstream tasks. We study the performance of this approach by benchmarking on over 30 different existing computer vision datasets, spanning tasks such as OCR, action recognition in videos, geo-localization, and many types of fine-grained object classification. The model transfers non-trivially to most tasks and is often competitive with a fully supervised baseline without the need for any dataset specific training. For instance, we match the accuracy of the original ResNet-50 on ImageNet zero-shot without needing to use any of the 1.28 million training examples it was trained on. We release our code and pre-trained model weights at https://github.com/OpenAI/CLIP.
translated by 谷歌翻译
我们从任务特定的BERT基教师模型执行知识蒸馏(KD)基准到各种学生模型:Bilstm,CNN,Bert-Tiny,Bert-Mini和Bert-small。我们的实验涉及在两个任务中分组的12个数据集:印度尼西亚语言中的文本分类和序列标记。我们还比较蒸馏的各个方面,包括使用Word Embeddings和未标记的数据增强的使用。我们的实验表明,尽管基于变压器的模型的普及程度不断上升,但是使用Bilstm和CNN学生模型,与修剪的BERT模型相比,使用Bilstm和CNN学生模型提供了性能和计算资源(CPU,RAM和存储)之间的最佳权衡。我们进一步提出了一些快速胜利,通过涉及涉及丢失功能,Word Embeddings和未标记的数据准备的简单选择的高效KD培训机制来生产小型NLP模型。
translated by 谷歌翻译
我们提出了Patron,这是一种新方法,它使用基于及时的不确定性估计,用于在冷启动场景下进行预训练的语言模型进行微调的数据选择,即,没有初始标记的数据可用。在顾客中,我们设计(1)一种基于迅速的不确定性传播方法来估计数据点的重要性和(2)分区 - 然后 - 剥离(PTR)策略,以促进对注释的样品多样性。六个文本分类数据集的实验表明,赞助人的表现优于最强的冷启动数据选择基准,高达6.9%。此外,仅具有128个标签,顾客分别基于香草微调和及时的学习,获得了91.0%和92.1%的全面监督性能。我们的赞助人实施可在\ url {https://github.com/yueyu1030/patron}上获得。
translated by 谷歌翻译
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
translated by 谷歌翻译
无需进行任何架构更改的微调审计语言模型(LMS)已成为学习下游任务各种语言的规范。但是,对于非语言下游任务,一种常见的做法是使用特定于任务的设计来进行输入,输出层和损失功能。例如,可以通过用图像补丁嵌入层替换单词嵌入层,带有10向输出层的单词图表输出层以及单词预测丢失,将LM微调为MNIST分类器。 - 分别分类损失。出现一个自然的问题:LM微调可以在不更改模型架构或损失功能的情况下解决非语言的下游任务吗?为了回答这一点,我们提出了语言交织的微调(LIFT),并通过对非语言分类和回归任务的套件进行广泛的经验研究来研究其功效和局限性。 Lift不会对模型体系结构或损失功能进行任何更改,它仅依赖于自然语言界面,从而使“使用LMS进行无代码机”学习。我们发现,在各种低维分类和回归任务中,LIFT的性能相对较好,在许多情况下匹配了最佳基线的性能,尤其是对于分类任务。我们报告了有关升力的基本特性的实验结果,包括其电感偏差,样品效率,推断出外推能力,对异常值的鲁棒性和标签噪声以及概括。我们还分析了一些特定于提升的属性/技术,例如,通过适当提示,预测不确定性量化和两阶段微调,上下文感知学习。我们的代码可从https://github.com/uw-madison-lee-lab/languageinterfacefacefacefinetuning获得。
translated by 谷歌翻译
将最新的变压器模型蒸馏成轻量级的学生模型是降低推理时计算成本的有效方法。学生模型通常是紧凑的变压器,参数较少,而昂贵的操作(例如自我发项)持续存在。因此,对于实时或大量用例,提高的推理速度仍然不令人满意。在本文中,我们旨在通过将教师模型提炼成更大,更稀疏的学生模型来进一步推动推理速度的极限 - 更大的是它们扩展到数十亿个参数;稀疏,大多数模型参数是N-gram嵌入。我们对六个单词文本分类任务的实验表明,这些学生模型平均保留了罗伯塔大师教师表现的97%,同时推理时GPU和CPU的加速速度最高为600倍。进一步的调查表明,我们的管道也有助于句子对分类任务和域泛化设置。
translated by 谷歌翻译
The recent GPT-3 model (Brown et al., 2020) achieves remarkable few-shot performance solely by leveraging a natural-language prompt and a few task demonstrations as input context. Inspired by their findings, we study few-shot learning in a more practical scenario, where we use smaller language models for which fine-tuning is computationally efficient. We present LM-BFF-better few-shot fine-tuning of language models 1 -a suite of simple and complementary techniques for finetuning language models on a small number of annotated examples. Our approach includes (1) prompt-based fine-tuning together with a novel pipeline for automating prompt generation; and (2) a refined strategy for dynamically and selectively incorporating demonstrations into each context. Finally, we present a systematic evaluation for analyzing few-shot performance on a range of NLP tasks, including classification and regression. Our experiments demonstrate that our methods combine to dramatically outperform standard fine-tuning procedures in this low resource setting, achieving up to 30% absolute improvement, and 11% on average across all tasks. Our approach makes minimal assumptions on task resources and domain expertise, and hence constitutes a strong task-agnostic method for few-shot learning. 2 * The first two authors contributed equally. 1 Alternatively, language models' best friends forever. 2 Our implementation is publicly available at https:// github.com/princeton-nlp/LM-BFF.
translated by 谷歌翻译
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.
translated by 谷歌翻译
One paradigm for learning from few labeled examples while making best use of a large amount of unlabeled data is unsupervised pretraining followed by supervised fine-tuning. Although this paradigm uses unlabeled data in a task-agnostic way, in contrast to common approaches to semi-supervised learning for computer vision, we show that it is surprisingly effective for semi-supervised learning on ImageNet. A key ingredient of our approach is the use of big (deep and wide) networks during pretraining and fine-tuning. We find that, the fewer the labels, the more this approach (task-agnostic use of unlabeled data) benefits from a bigger network. After fine-tuning, the big network can be further improved and distilled into a much smaller one with little loss in classification accuracy by using the unlabeled examples for a second time, but in a task-specific way. The proposed semi-supervised learning algorithm can be summarized in three steps: unsupervised pretraining of a big ResNet model using SimCLRv2, supervised fine-tuning on a few labeled examples, and distillation with unlabeled examples for refining and transferring the task-specific knowledge. This procedure achieves 73.9% ImageNet top-1 accuracy with just 1% of the labels (≤13 labeled images per class) using ResNet-50, a 10× improvement in label efficiency over the previous state-of-theart. With 10% of labels, ResNet-50 trained with our method achieves 77.5% top-1 accuracy, outperforming standard supervised training with all of the labels. 1
translated by 谷歌翻译
Language models (LMs) have demonstrated remarkable performance on downstream tasks, using in-context exemplars or human instructions. Recent works have shown that chain-of-thought (CoT) prompting can elicit models to solve complex reasoning tasks, step-by-step. However, the efficacy of prompt-based CoT methods is restricted to very large LMs such as GPT-3 (175B), thus limiting deployability. In this paper, we revisit the fine-tuning approach to enable complex reasoning in smaller LMs, optimized to efficiently perform a specific task. We propose Fine-tune-CoT, a method that leverages the capabilities of very large LMs to generate reasoning samples and teach smaller models via fine-tuning. We evaluate our method on publicly available LMs across a wide range of complex tasks and model sizes. We find that Fine-tune-CoT enables substantial reasoning capability in small models, whereas previous prompt-based baselines exhibit near-random performance. Student models can even outperform the teacher in some tasks while reducing model size requirements by several orders of magnitude. We conduct extensive ablations and sample studies to understand the reasoning capabilities of student models. We also identify several important nuances that have been overlooked in concurrent fine-tuning works on CoT and address them in our analysis.
translated by 谷歌翻译
This work tackles the problem of semi-supervised learning of image classifiers. Our main insight is that the field of semi-supervised learning can benefit from the quickly advancing field of self-supervised visual representation learning. Unifying these two approaches, we propose the framework of self-supervised semi-supervised learning (S 4 L) and use it to derive two novel semi-supervised image classification methods. We demonstrate the effectiveness of these methods in comparison to both carefully tuned baselines, and existing semi-supervised learning methods. We then show that S 4 L and existing semi-supervised methods can be jointly trained, yielding a new state-of-the-art result on semi-supervised ILSVRC-2012 with 10% of labels.
translated by 谷歌翻译
Natural language prompts have been shown to facilitate cross-task generalization for large language models. However, with no or limited labeled examples, the cross-task performance is highly sensitive to the choice of prompts, while selecting a high-performing prompt is challenging given the scarcity of labels. To address the issue, we propose a Zero-Label Prompt Selection (ZPS) method that selects prompts without any labeled data or gradient update. Specifically, given the candidate human-written prompts for a task, ZPS labels a set of unlabeled data with a prompt ensemble and uses the pseudo-labels for prompt selection. Experiments show that ZPS improves over prior methods by a sizeable margin in zero-label performance. We also extend ZPS to a few-shot setting and show its advantages over strong baselines such as prompt tuning and model tuning.
translated by 谷歌翻译
We demonstrate that scaling up language models greatly improves task-agnostic, few-shot performance, sometimes even becoming competitive with prior state-ofthe-art fine-tuning approaches. Specifically, we train GPT-3, an autoregressive language model with 175 billion parameters, 10x more than any previous nonsparse language model, and test its performance in the few-shot setting. For all tasks, GPT-3 is applied without any gradient updates or fine-tuning, with tasks and few-shot demonstrations specified purely via text interaction with the model. GPT-3 achieves strong performance on many NLP datasets, including translation, question-answering, and cloze tasks. We also identify some datasets where GPT-3's few-shot learning still struggles, as well as some datasets where GPT-3 faces methodological issues related to training on large web corpora.
translated by 谷歌翻译
We present Noisy Student Training, a semi-supervised learning approach that works well even when labeled data is abundant. Noisy Student Training achieves 88.4% top-1 accuracy on ImageNet, which is 2.0% better than the state-of-the-art model that requires 3.5B weakly labeled Instagram images. On robustness test sets, it improves ImageNet-A top-1 accuracy from 61.0% to 83.7%, reduces ImageNet-C mean corruption error from 45.7 to 28.3, and reduces ImageNet-P mean flip rate from 27.8 to 12.2.Noisy Student Training extends the idea of self-training and distillation with the use of equal-or-larger student models and noise added to the student during learning. On Im-ageNet, we first train an EfficientNet model on labeled images and use it as a teacher to generate pseudo labels for 300M unlabeled images. We then train a larger Efficient-Net as a student model on the combination of labeled and pseudo labeled images. We iterate this process by putting back the student as the teacher. During the learning of the student, we inject noise such as dropout, stochastic depth, and data augmentation via RandAugment to the student so that the student generalizes better than the teacher. 1 * This work was conducted at Google.
translated by 谷歌翻译
Despite significant advances, the performance of state-of-the-art continual learning approaches hinges on the unrealistic scenario of fully labeled data. In this paper, we tackle this challenge and propose an approach for continual semi-supervised learning -- a setting where not all the data samples are labeled. An underlying issue in this scenario is the model forgetting representations of unlabeled data and overfitting the labeled ones. We leverage the power of nearest-neighbor classifiers to non-linearly partition the feature space and learn a strong representation for the current task, as well as distill relevant information from previous tasks. We perform a thorough experimental evaluation and show that our method outperforms all the existing approaches by large margins, setting a strong state of the art on the continual semi-supervised learning paradigm. For example, on CIFAR100 we surpass several others even when using at least 30 times less supervision (0.8% vs. 25% of annotations).
translated by 谷歌翻译