Fine Tuning Target Tasks的连续提示最近被出现为完整模型微调的紧凑替代方案。这些有前途的结果的动机,我们调查了提取离散(文本)解释的可行性,持续提示忠于他们解决的问题。在实践中,我们在通过连续提示和最近的邻离分立投影解决的任务之间的“任性”行为:我们可以找到解决任务的连续提示,同时投射到任意文本(例如,不同甚至a的定义矛盾的任务),而在最佳连续提示的非常小(2%)的边缘内,对于任务相同的相同尺寸。我们提供这种奇怪和令人惊讶的行为背后的直觉,以及广泛的实证分析量化各种参数的效果。例如,对于更大的模型大小,我们观察到更高的任性,即,我们可以发现提示更紧密地映射到任何随意的任意文本,精度较小。这些调查结果与忠实地解释模型和任务持续提示及其概括的难度有关的重要意义,为提示语言模型的未来进展提供指导。
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Large language models can perform new tasks in a zero-shot fashion, given natural language prompts that specify the desired behavior. Such prompts are typically hand engineered, but can also be learned with gradient-based methods from labeled data. However, it is underexplored what factors make the prompts effective, especially when the prompts are natural language. In this paper, we investigate common attributes shared by effective prompts. We first propose a human readable prompt tuning method (F LUENT P ROMPT) based on Langevin dynamics that incorporates a fluency constraint to find a diverse distribution of effective and fluent prompts. Our analysis reveals that effective prompts are topically related to the task domain and calibrate the prior probability of label words. Based on these findings, we also propose a method for generating prompts using only unlabeled data, outperforming strong baselines by an average of 7.0% accuracy across three tasks.
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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.
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In this work, we explore "prompt tuning," a simple yet effective mechanism for learning "soft prompts" to condition frozen language models to perform specific downstream tasks. Unlike the discrete text prompts used by GPT-3, soft prompts are learned through backpropagation and can be tuned to incorporate signals from any number of labeled examples. Our end-to-end learned approach outperforms GPT-3's few-shot learning by a large margin. More remarkably, through ablations on model size using T5, we show that prompt tuning becomes more competitive with scale: as models exceed billions of parameters, our method "closes the gap" and matches the strong performance of model tuning (where all model weights are tuned). This finding is especially relevant because large models are costly to share and serve and the ability to reuse one frozen model for multiple downstream tasks can ease this burden. Our method can be seen as a simplification of the recently proposed "prefix tuning" of Li and Liang (2021) and we provide a comparison to this and other similar approaches. Finally, we show that conditioning a frozen model with soft prompts confers benefits in robustness to domain transfer and enables efficient "prompt ensembling." * Work done as a Google AI Resident.
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GPT-3显示了培训的大规模语言模型(LMS)的卓越情调学习能力,培训数十亿规模数据。在这里,我们解决了GPT-3纸张报告的一些剩余问题,例如非英语LM,不同大小模型的性能,以及最近引入的迅速优化对上下文学习的效果。为实现这一目标,我们介绍了HyperClova,一个韩国VPT-3的韩国变体训练在一个以韩国为中心的560b标准的令牌。通过我们的韩国特定标记化,HyperClova与我们的培训配置增强,显示了韩国各种下游任务的最先进的上下游零射击和几秒钟学习表演。此外,我们展示了基于及时的学习的性能优势,并演示如何集成到迅速的工程管道中。然后,我们讨论了通过引入Hyperclova Studio,互动提示工程界面向ML的非专家提供AI原型设计能力来实现No Code AI范例的可能性。最后,我们展示了我们具有三个成功的内部应用程序的方法的潜力。
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本文探讨了提高语言模型的零次学习能力的简单方法。我们表明,指令调整 - 通过对说明书中所述的任务集合微调语言模型 - 大幅提升零射门上看不见任务中的表现。我们采取预训练的语言模型和指令调整它通过自然语言指令模板语言表达了60NLP任务137B参数。我们评估这种指令调整模型,我们称之为FLAN,在看不见的任务类型。FLAN显着改善其未修饰的对应的性能和超过25的20个任务,我们评估零射门175BGPT-3。FLAN甚至GPT-3通过在安利,RTE,BoolQ,AI2-ARC,OpenbookQA和StoryCloze大比分胜过几拍。消融研究显示任务和模型的规模,这个数字是指令调整取得成功的关键组成部分。
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诸如剪辑之类的大型预训练的视觉模型在学习表现方面表现出巨大的潜力,这些模型可以在各种下游任务中转移。与主要基于离散标签的传统表示学习不同,视觉语言预训练会使图像和文本在公共特征空间中对齐,这允许通过提示零弹性转移到下游任务,即从分类权重合成。描述兴趣类的自然语言。在这项工作中,我们表明,在实践中部署此类模型的一个重大挑战是及时的工程,它需要域专业知识,并且非常耗时 - 由于措辞的略有变化,需要花费大量时间来进行单词调整可能会对性能产生巨大影响。受到自然语言处理(NLP)迅速学习研究的最新进展的启发,我们提出了上下文优化(COP),这是一种专门用于调整类似剪辑的视觉语言模型的简单方法,用于下游图像识别。具体而言,Coop用可学习的向量建模了提示A的上下文单词,而整个预训练的参数则保持固定。为了处理不同的图像识别任务,我们提供了两个COOP的实现:统一上下文和特定于班级的上下文。通过在11个数据集上进行的大量实验,我们证明Coop只需要一两个镜头才能以相当的利润击败手工制作的提示,并且能够以16张镜头(例如16张照片)获得迅速工程的显着改进增益约为15%(最高达到45%以上)。尽管是一种基于学习的方法,但与使用手工制作的提示相比,Coop与零拍模型相比,取得了出色的域泛化性能。
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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.
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We describe PromptBoosting, a query-efficient procedure for building a text classifier from a neural language model (LM) without access to the LM's parameters, gradients, or hidden representations. This form of "black-box" classifier training has become increasingly important as the cost of training and inference in large-scale LMs grows. But existing black-box LM classifier learning approaches are themselves computationally inefficient, typically specializing LMs to the target task by searching in a large space of (discrete or continuous) prompts using zeroth-order optimization methods. Instead of directly optimizing in prompt space, PromptBoosting obtains a small pool of prompts via a gradient-free approach and then constructs a large pool of weak learners by pairing these prompts with different elements of the LM's output distribution. These weak learners are then ensembled using the AdaBoost algorithm. The entire learning process requires only a small number of forward passes and no backward pass. Experiments show that PromptBoosting achieves state-of-the-art performance in multiple black-box few-shot classification tasks, and matches or outperforms full fine-tuning in both few-shot and standard learning paradigms, while training 10x faster than existing black-box methods.
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Pre-trained large language models can efficiently interpolate human-written prompts in a natural way. Multitask prompted learning can help generalization through a diverse set of tasks at once, thus enhancing the potential for more effective downstream fine-tuning. To perform efficient multitask-inference in the same batch, parameter-efficient fine-tuning methods such as prompt tuning have been proposed. However, the existing prompt tuning methods may lack generalization. We propose SPT, a semi-parametric prompt tuning method for multitask prompted learning. The novel component of SPT is a memory bank from where memory prompts are retrieved based on discrete prompts. Extensive experiments, such as (i) fine-tuning a full language model with SPT on 31 different tasks from 8 different domains and evaluating zero-shot generalization on 9 heldout datasets under 5 NLP task categories and (ii) pretraining SPT on the GLUE datasets and evaluating fine-tuning on the SuperGLUE datasets, demonstrate effectiveness of SPT.
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Language models can be prompted to perform a wide variety of zero- and few-shot learning problems. However, performance varies significantly with the choice of prompt, and we do not yet understand why this happens or how to pick the best prompts. In this work, we analyze the factors that contribute to this variance and establish a new empirical hypothesis: the performance of a prompt is coupled with the extent to which the model is familiar with the language it contains. Over a wide range of tasks, we show that the lower the perplexity of the prompt is, the better the prompt is able to perform the task. As a result, we devise a method for creating prompts: (1) automatically extend a small seed set of manually written prompts by paraphrasing using GPT3 and backtranslation and (2) choose the lowest perplexity prompts to get significant gains in performance.
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参数效率的方法能够使用单个冷冻的预训练的大语言模型(LLM)来通过学习特定于任务的软提示来执行许多任务,从而在串联到输入文本时调节模型行为。但是,这些学习的提示与给定的冷冻模型紧密耦合 - 如果模型已更新,则需要获得相应的新提示。在这项工作中,我们提出并调查了几种“提示回收”的方法,其中将在源模型上进行了及时培训以与新目标模型一起使用。我们的方法不依赖于目标模型的有监督的提示,特定于任务的数据或培训更新,这与从头开始的目标模型重新调整提示一样昂贵。我们表明,模型之间的回收是可能的(我们的最佳设置能够成功回收$ 88.9 \%的提示,从而产生一个提示,即表现出色的基线),但是剩下的大量性能净空,需要改进的回收技术。
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Existing techniques for training language models can be misaligned with the truth: if we train models with imitation learning, they may reproduce errors that humans make; if we train them to generate text that humans rate highly, they may output errors that human evaluators can't detect. We propose circumventing this issue by directly finding latent knowledge inside the internal activations of a language model in a purely unsupervised way. Specifically, we introduce a method for accurately answering yes-no questions given only unlabeled model activations. It works by finding a direction in activation space that satisfies logical consistency properties, such as that a statement and its negation have opposite truth values. We show that despite using no supervision and no model outputs, our method can recover diverse knowledge represented in large language models: across 6 models and 10 question-answering datasets, it outperforms zero-shot accuracy by 4\% on average. We also find that it cuts prompt sensitivity in half and continues to maintain high accuracy even when models are prompted to generate incorrect answers. Our results provide an initial step toward discovering what language models know, distinct from what they say, even when we don't have access to explicit ground truth labels.
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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。
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The remarkable success of pretrained language models has motivated the study of what kinds of knowledge these models learn during pretraining. Reformulating tasks as fillin-the-blanks problems (e.g., cloze tests) is a natural approach for gauging such knowledge, however, its usage is limited by the manual effort and guesswork required to write suitable prompts. To address this, we develop AUTOPROMPT, an automated method to create prompts for a diverse set of tasks, based on a gradient-guided search. Using AUTO-PROMPT, we show that masked language models (MLMs) have an inherent capability to perform sentiment analysis and natural language inference without additional parameters or finetuning, sometimes achieving performance on par with recent state-of-the-art supervised models. We also show that our prompts elicit more accurate factual knowledge from MLMs than the manually created prompts on the LAMA benchmark, and that MLMs can be used as relation extractors more effectively than supervised relation extraction models. These results demonstrate that automatically generated prompts are a viable parameter-free alternative to existing probing methods, and as pretrained LMs become more sophisticated and capable, potentially a replacement for finetuning.
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在本文中,我们描述了我们参与Case-2022的子任务1,即与休闲新闻语料库的事件因果关系识别。我们通过在少数带注释的示例(即几次配置)上利用一组简单但互补的技术来解决因果关系识别(CRI)任务。我们遵循一种基于迅速的预测方法,用于微调LMS,其中CRI任务被视为掩盖语言建模问题(MLM)。这种方法允许LMS在MLM问题上进行本地预先训练,可以直接生成对CRI特异性提示的文本响应。我们将此方法的性能与在整个数据集中训练的集合技术进行比较。我们表现​​最佳的提交仅接受了每班256个实例,整个数据集的一小部分培训,但能够获得第二好的精度(0.82),第三好的精度(0.82)和F1得分。 (0.85)非常接近获胜者团队(0.86)的报道。
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Recent work has presented intriguing results examining the knowledge contained in language models (LM) by having the LM fill in the blanks of prompts such as "Obama is a by profession". These prompts are usually manually created, and quite possibly suboptimal; another prompt such as "Obama worked as a " may result in more accurately predicting the correct profession. Because of this, given an inappropriate prompt, we might fail to retrieve facts that the LM does know, and thus any given prompt only provides a lower bound estimate of the knowledge contained in an LM. In this paper, we attempt to more accurately estimate the knowledge contained in LMs by automatically discovering better prompts to use in this querying process. Specifically, we propose mining-based and paraphrasing-based methods to automatically generate high-quality and diverse prompts, as well as ensemble methods to combine answers from different prompts. Extensive experiments on the LAMA benchmark for extracting relational knowledge from LMs demonstrate that our methods can improve accuracy from 31.1% to 39.6%, providing a tighter lower bound on what LMs know. We have released the code and the resulting LM Prompt And Query Archive (LPAQA) at https://github. com/jzbjyb/LPAQA.1 Some models we use in this paper, e.g. BERT (Devlin et al., 2019), are bi-directional, and do not directly define probability distribution over text, which is the underlying definition of an LM. Nonetheless, we call them LMs for simplicity.
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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.
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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。
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Traditional multi-task learning architectures train a single model across multiple tasks through a shared encoder followed by task-specific decoders. Learning these models often requires specialized training algorithms that address task-conflict in the shared parameter updates, which otherwise can lead to negative transfer. A new type of multi-task learning within NLP homogenizes multi-task architectures as a shared encoder and language model decoder, which does surprisingly well across a range of diverse tasks. Does this new architecture suffer from task-conflicts that require specialized training algorithms? We study how certain factors in the shift towards text-to-text models affects multi-task conflict and negative transfer, finding that both directional conflict and transfer are surprisingly constant across architectures.
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