我们通过与与前面令牌的局部相似度,通过调节从大语料库检索的文档块来增强自动回归语言模型。尽管使用25美元\时分,我们的检索增强型变压器(RetroCro)的检索增强型变压器(RetroCr)对GPT-3和侏罗纪-1获得了可比性的性能。微调后,复古表演转换为下游知识密集型任务,如问题应答。复古结合了冷冻BERT猎犬,一种可微分的编码器和块状的横向机制,以预测基于数量级的令牌,而不是训练期间通常消耗的数量。我们通常从头开始训练复古,还可以快速改造预先接受的变压器,通过检索,仍然达到良好的性能。我们的工作通过以前所未有的规模开辟了通过显式内存改进语言模型的新途径。
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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。
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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.
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Natural language processing tasks, such as question answering, machine translation, reading comprehension, and summarization, are typically approached with supervised learning on taskspecific datasets. We demonstrate that language models begin to learn these tasks without any explicit supervision when trained on a new dataset of millions of webpages called WebText. When conditioned on a document plus questions, the answers generated by the language model reach 55 F1 on the CoQA dataset -matching or exceeding the performance of 3 out of 4 baseline systems without using the 127,000+ training examples. The capacity of the language model is essential to the success of zero-shot task transfer and increasing it improves performance in a log-linear fashion across tasks. Our largest model, GPT-2, is a 1.5B parameter Transformer that achieves state of the art results on 7 out of 8 tested language modeling datasets in a zero-shot setting but still underfits WebText. Samples from the model reflect these improvements and contain coherent paragraphs of text. These findings suggest a promising path towards building language processing systems which learn to perform tasks from their naturally occurring demonstrations.
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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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在这项工作中,我们证明了多种语的大规模序列到序列(SEQ2SEQ)模型,该模型是通过Denoising和因果语言建模(CLM)任务的混合物进行训练的,比仅解码器模型更有效地进行了效率的学习者在各种任务上。特别是,我们培训了一个名为Alexa教师模型(Alexatm 20b)的200亿个参数多语言SEQ2SEQ模型,并表明它在1-Shot摘要任务上实现了最先进的(SOTA)性能,超过了更大的540B PALM DOPODER模型。 Alexatm 20b还可以在1-Shot Machine翻译中实现SOTA,尤其是对于低资源语言,几乎所有语言对(阿拉伯语,英语,法语,德语,德语,印地语,意大利语,日语,以及flores-101数据集上的泰卢固语)。我们还显示了零拍设置,AlexATM 20B在SuperGlue和SqueadV2数据集上的表现优于GPT3(175B),并在XNLI,XCOPA,PAWS-X和XWINOGRAD等多语言任务上提供SOTA性能。总体而言,我们的结果为SEQ2SEQ模型提供了一个令人信服的案例,作为大型语言模型(LLM)培训的仅解码器模型的强大替代方法。
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我们表明,在将直接转换应用到数据集之后,自回归语言模型可以学会填充文本,这简单地将文本的跨度从文档的中间移动到了其末尾。虽然近年来这种数据增强引起了人们的极大兴趣,但我们提供了广泛的证据,表明以这种方式转换的数据很大一部分并不会损害原始的左右生成能力,这是通过困惑和抽样评估来衡量的广泛的尺度。鉴于培训模型对中间的有用性,简单性和效率(FIM),我们建议默认情况下使用FIM培训未来的自回归语言模型。为此,我们在关键的超参数上运行一系列消融,例如数据转换频率,转换的结构以及选择填充跨度的方法。我们使用这些消融来规定强大的默认设置和最佳实践来训练FIM模型。我们发布了最佳的填充模型,该模型在API中培训了最佳实践,并发布了我们的填充基准,以帮助未来的研究。
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Transformers-based models, such as BERT, have been one of the most successful deep learning models for NLP. Unfortunately, one of their core limitations is the quadratic dependency (mainly in terms of memory) on the sequence length due to their full attention mechanism. To remedy this, we propose, BIGBIRD, a sparse attention mechanism that reduces this quadratic dependency to linear. We show that BIGBIRD is a universal approximator of sequence functions and is Turing complete, thereby preserving these properties of the quadratic, full attention model. Along the way, our theoretical analysis reveals some of the benefits of having O(1) global tokens (such as CLS), that attend to the entire sequence as part of the sparse attention mechanism. The proposed sparse attention can handle sequences of length up to 8x of what was previously possible using similar hardware. As a consequence of the capability to handle longer context, BIGBIRD drastically improves performance on various NLP tasks such as question answering and summarization. We also propose novel applications to genomics data.
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我们介绍了块状变压器,该变压器以序列的反复方式应用变压器层,并且相对于序列长度具有线性复杂性。我们的复发单元在训练过程中在代币的块而不是单个令牌上运行,并利用块内并行计算,以便有效利用加速器硬件。单元本身非常简单。它仅仅是一个变压器层:它使用自我注意事项和交叉注意力来有效计算大量状态向量和令牌上的复发函数。我们的设计部分受到LSTM单元的启发,它使用LSTM风格的大门,但它可以将典型的LSTM单元缩放为几个数量级。我们的复发实现在计算时间和参数计数中都具有相同的成本作为传统的变压器层,但是在很长的序列中,语言建模任务中的语言建模任务的困惑极大地改善了。我们的模型比远程变压器XL基线的表现宽大,同时运行的速度是两倍。我们证明了它在PG19(书籍),Arxiv论文和GitHub源代码上的有效性。我们的代码已发布为开​​源。
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Recent work has improved language models (LMs) remarkably by equipping them with a non-parametric memory component. However, most existing approaches only introduce mem-ories at testing time or represent them using a separately trained encoder, resulting in suboptimal training of the language model. In this work, we present TRIME, a novel yet simple training approach designed for training LMs with memory augmentation. Our approach uses a training objective that directly takes in-batch examples as accessible memory. We also present new methods for memory construction and data batching, which are used for adapting to different sets of memories--local, long-term, and external memory--at testing time. We evaluate TRIME on multiple language modeling and machine translation benchmarks and show that it is able to achieve significant improvements across all the settings. Concretely, TRIME reduces the perplexity from 18.70 to 15.37 on WIKITEXT-103, by effectively leveraging a large memory set from the training corpus. Compared to standard LM training, TRIME adds negligible computational overhead and is compatible with different neural architectures, making it a versatile solution for training memory-augmented LMs.
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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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几乎没有射击的内在学习(ICL)使预训练的语言模型能够通过为输入的一部分提供少量的培训示例来执行以前的任务,而无需任何基于梯度的培训。 ICL会产生大量的计算,内存和存储成本,因为它每次进行预测时都涉及处理所有培训示例。参数有效的微调(PEFT)(例如,适配器模块,提示调谐,稀疏更新方法等)提供了替代范式,其中训练了一组少量参数以启用模型来执行新任务。在本文中,我们严格地比较了几个ICL和PEFT,并证明后者提供了更好的准确性,并大大降低了计算成本。在此过程中,我们引入了一种称为(IA)$^3 $的新PEFT方法,该方法通过学习的向量来扩展激活,从而获得更强的性能,同时仅引入相对少量的新参数。我们还提出了一个基于称为T-FEW的T0模型的简单食谱,可以将其应用于新任务,而无需特定于任务的调整或修改。我们通过将T-FEW应用于木筏基准,首次实现超人性能,并以6%的绝对性能优于最先进的方法来验证T-FEW对完全看不见的任务的有效性。我们实验中使用的所有代码均可公开使用。
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现实世界中的数据是高维的:即使在压缩后,书籍,图像或音乐表演也很容易包含数十万个元素。但是,最常用的自回归模型,变压器非常昂贵,以缩放捕获这种远程结构所需的输入和层数。我们开发了感知者AR,这是一种自回归的模态 - 不合骨架构,它使用交叉注意力将远程输入映射到少数潜在的潜在,同时还可以维护端到端的因果关系掩盖。感知器AR可以直接进行十万个令牌,从而实现了实用的长篇小写密度估计,而无需手工制作的稀疏模式或记忆机制。当对图像或音乐进行培训时,感知器AR会生成具有清晰长期连贯性和结构的输出。我们的架构还获得了长期基准测试的最新可能性,包括64 x 64个Imagenet图像和PG-19书籍。
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我们介绍了Sparrow,这是一个寻求信息的对话代理,与提示的语言模型基线相比,训练有素,更有帮助,正确和无害。我们使用从人类反馈中的强化学习来培训我们的模型,以帮助人类评估者判断代理人的行为。首先,为了使我们的代理人更有帮助和无害,我们将良好对话的要求分解为代理人应遵循的自然语言规则,并分别向评估者询问每个规则。我们证明,这种崩溃使我们能够收集对代理行为的更多针对性的人类判断,并允许更有效的规则条件奖励模型。其次,我们的代理商在收集对模型声明的偏好判决时提供了支持事实主张的来源的证据。对于事实问题,麻雀提供的证据支持了78%的时间。比基线比基线更享受麻雀,同时对人类的对抗性探测更具弹性,在探测时只有8%的时间违反了我们的规则。最后,我们进行了广泛的分析,表明尽管我们的模型学会遵守我们的规则,但它可以表现出分布偏见。
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Recent work has shown that fine-tuning large pre-trained language models on a collection of tasks described via instructions, a.k.a. instruction-tuning, improves their zero and few-shot generalization to unseen tasks. However, there is a limited understanding of the performance trade-offs of different decisions made during the instruction-tuning process. These decisions include the scale and diversity of the instruction-tuning benchmark, different task sampling strategies, fine-tuning with and without demonstrations, training using specialized datasets for reasoning and dialogue, and finally, the fine-tuning objectives themselves. In this paper, we characterize the effect of instruction-tuning decisions on downstream task performance when scaling both model and benchmark sizes. To this end, we create OPT-IML Bench: a large benchmark for Instruction Meta-Learning (IML) of 2000 NLP tasks consolidated into task categories from 8 existing benchmarks, and prepare an evaluation framework to measure three types of model generalizations: to tasks from fully held-out categories, to held-out tasks from seen categories, and to held-out instances from seen tasks. Through the lens of this framework, we first present insights about instruction-tuning decisions as applied to OPT-30B and further exploit these insights to train OPT-IML 30B and 175B, which are instruction-tuned versions of OPT. OPT-IML demonstrates all three generalization abilities at both scales on four different evaluation benchmarks with diverse tasks and input formats -- PromptSource, FLAN, Super-NaturalInstructions, and UnifiedSKG. Not only does it significantly outperform OPT on all benchmarks but is also highly competitive with existing models fine-tuned on each specific benchmark. We release OPT-IML at both scales, together with the OPT-IML Bench evaluation framework.
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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.
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GPT-3等大型自回归语言模型是几秒钟的学习者,可以在没有微调的情况下执行各种语言任务。虽然已知这些模型能够共同代表许多不同的语言,但他们的培训数据由英语主导,可能限制了它们的交叉概括。在这项工作中,我们在覆盖多种语言的平衡语料库上培训多语言自回归语言模型,并在广泛的任务中研究他们几乎没有零点的学习能力。我们最大的模型,具有75亿参数,在20多种代表语言中,在几种代表语言中,在几种代表性语言中,在几种代表性语言中,在多语言型号推理中表现出可比大小的GPT-3(在0次设置和0次拍摄设置中的绝对精度改善+ 7.4% 4-拍摄设置中的9.4%)和自然语言推理(每次拍摄和4次设置中的每一个+ 5.4%)。在Flores-101机器翻译基准测试中,我们的模型优于GPT-3在182个翻译方向上有32个培训例子,同时超过45个方向的官方监督基线。我们介绍了模型成功和失败的位置的详细分析,特别是它尤其显示在某些任务中实现交叉语境的内容学习,而仍然存在改善表面的鲁棒性和适应没有a的任务的余地自然冻结形式。最后,我们评估我们在仇恨语音检测中以五种语言的仇恨语音检测的模型,并发现它具有与可比大小的GPT-3模型类似的限制。
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鉴于大型语言模型的广泛能力,应该有可能朝着一般的文本的助手工作,这些助手与人类价值一致,这意味着它是有帮助,诚实的和无害的。在此方向上的初始遗传,我们研究简单的基线技术和评估,例如提示。我们发现,从模型规模增加适度的干预措施的好处,概括为各种对准评估,并不会损害大型模型的性能。接下来,我们调查与对齐,比较仿制,二进制歧视和排名偏好建模相关的几个培训目标的缩放趋势。我们发现排名优先级模型比模仿学习更好地表现得多,并且通常以模型大小更有利地缩放。相比之下,二进制歧视通常与模仿学习非常类似地执行和缩放。最后,我们研究了一种“偏好模型预训练阶段的培训阶段,其目的是在对人偏好的芬明时提高样本效率。
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当前的语言模型可以产生高质量的文本。他们只是复制他们之前看到的文本,或者他们学习了普遍的语言抽象吗?要取笑这些可能性,我们介绍了乌鸦,这是一套评估生成文本的新颖性,专注于顺序结构(n-gram)和句法结构。我们将这些分析应用于四种神经语言模型(LSTM,变压器,变换器-XL和GPT-2)。对于本地结构 - 例如,单个依赖性 - 模型生成的文本比来自每个模型的测试集的人类生成文本的基线显着不那么新颖。对于大规模结构 - 例如,总句结构 - 模型生成的文本与人生成的基线一样新颖甚至更新颖,但模型仍然有时复制,在某些情况下,在训练集中重复超过1000字超过1,000字的通道。我们还表现了广泛的手动分析,表明GPT-2的新文本通常在形态学和语法中形成良好,但具有合理的语义问题(例如,是自相矛盾)。
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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。
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