尽管大型预训练的模型已在各种下游任务上取得了令人印象深刻的结果，但最大的现有模型仍然会犯错，甚至准确的预测可能会随着时间的流逝而过时。因为在训练时间检测所有此类故障是不可能的，因此可以使此类模型的开发人员和最终用户能够纠正不准确的输出，同时希望将模型保持完整。但是，大型神经网络学到的表示形式的分布式黑盒性质使得产生这种目标编辑困难。如果仅出现单个有问题的输入和新的所需输出，则微调方法往往过于fit。当应用于非常大的模型时，其他编辑算法在计算上是不可行的，要么简单地无效。为了启用大规模的简单事后编辑，我们建议使用梯度分解（MEND）提出模型编辑器网络，该网络是一个小型辅助编辑网络的集合，该网络使用单个所需的输入输出对将快速的本地编辑对预先训练的模型进行快速的本地编辑。行为。 MEND学习使用标准微调获得的梯度，使用梯度的低排放分解来使该转换可牵引的参数化。即使在100亿+参数模型中，也可以在不到一天的时间内对单个GPU进行修订；经过训练的修补后，可以将新编辑快速应用于预训练的模型。我们对T5，GPT，BERT和BART模型的实验表明，MEND是模型编辑的唯一方法，该方法有效地编辑了具有超过100亿参数的模型的行为。代码和数据可在https://sites.google.com/view/mend-editing。

即使是最大的神经网络也会出错，随着世界的变化，曾经纠正的预测可能变得无效。模型编辑器对基础模型（预训练）模型的行为进行本地更新，以注入更新的知识或纠正不良行为。现有的模型编辑已经显示出希望，但也没有足够的表现力：他们难以准确地对编辑的预期范围进行建模（受编辑影响的示例），从而导致与编辑相关的测试输入的预测不准确，并且经常在之后完全失败。许多编辑。作为一个较高容量的替代方案，我们建议使用检索型反面模型（SERAC）提出半参数编辑，该模型（SERAC）存储在明确的内存中，并学会对它们进行推理以根据需要调节基本模型的预测。为了实现对模型编辑器的更严格评估，我们介绍了三个具有挑战性的语言模型编辑问题，基于问题回答，事实检查和对话生成。我们发现，只有SERAC才能在所有三个问题上实现高性能，从而超过了现有的方法，可以通过大量利润进行模型编辑。代码，数据和其他项目信息将在https://sites.google.com/view/serac-editing上提供。

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。

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。

语言模型是否存在对世界的信念？ Dennett（1995年）着名的据称，即使是恒温器也有信仰，认为，信仰只是一种与任何动机国家分离的信息状态。在本文中，我们讨论了何时何时对世界的信仰何时对世界的信念进行检测，并且我们改进了更新模型信念的方法更加真实，重点是基于学习优化器或HyperNetwork的方法。我们的主要贡献包括：（1）评估信仰更新方法的新指标，重点关注信仰的逻辑一致性，（2）培训目标，用于顺序，本地和概括模型更新（渣），从而提高学习优化器的性能（3）介绍信仰图，这是一种新的界面，语言模型显示模型信仰之间的相互依赖性。我们的实验表明，模型只有有限的程度才具有相信的品质，但更新方法都可以修复不正确的模型信念，并大大提高了它们的一致性。虽然现成的优化器令人惊讶地强烈的信念更新基线，但我们所学的优化器可以在更困难的环境中赢得比过去的工作更困难。代码可在https://github.com/peterbhase/slag-belifapdating中获得

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.

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.

Changing how pre-trained models behave -- e.g., improving their performance on a downstream task or mitigating biases learned during pre-training -- is a common practice when developing machine learning systems. In this work, we propose a new paradigm for steering the behavior of neural networks, centered around \textit{task vectors}. A task vector specifies a direction in the weight space of a pre-trained model, such that movement in that direction improves performance on the task. We build task vectors by subtracting the weights of a pre-trained model from the weights of the same model after fine-tuning on a task. We show that these task vectors can be modified and combined together through arithmetic operations such as negation and addition, and the behavior of the resulting model is steered accordingly. Negating a task vector decreases performance on the target task, with little change in model behavior on control tasks. Moreover, adding task vectors together can improve performance on multiple tasks at once. Finally, when tasks are linked by an analogy relationship of the form ``A is to B as C is to D", combining task vectors from three of the tasks can improve performance on the fourth, even when no data from the fourth task is used for training. Overall, our experiments with several models, modalities and tasks show that task arithmetic is a simple, efficient and effective way of editing models.

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。

我们为大规模训练的大规模训练语言模型提供了更简单，更稀疏，更快的算法，这些算法在许多标准的NLP任务上实现了最新的隐私与实用性权衡。我们为此问题提出了一个元框架，这是受高度参数效率方法进行微调成功的启发。我们的实验表明，这些方法的差异化适应能力在三个重要方面优于以前的私人算法：实用程序，隐私以及私人培训的计算和记忆成本。在许多经常研究的数据集中，私人模型的实用性接近了非私人模型的方法。例如，在MNLI数据集上，我们使用Roberta-large的准确度为87.8 \％$，使用Roberta-Base $ 83.5 \％$，其隐私预算为$ \ Epsilon = 6.7 $。相比之下，缺乏隐私限制，罗伯塔·莱格（Roberta-Large）的准确度为$ 90.2 \％$。我们的发现对于自然语言生成任务类似。与DART，GPT-2-SMALL，GPT-2中，GPT-2-MEDIUM，GPT-2-LARGE和GPT-2-XL的私人微调达到38.5、42.0、43.1和43.8（$ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 43.8） epsilon = 6.8，\ delta = $ 1E-5），而非私人基线为$ 48.1 $。我们所有的实验都表明，较大的模型更适合私人微调：虽然众所周知，它们旨在非优先实现卓越的准确性，但我们发现当引入隐私时，它们也更好地保持其准确性。

大型审慎的语言模型（PLM）通常是通过微调或提示来适应域或任务的。填充需要修改所有参数，并具有足够的数据以避免过度拟合，同时提示不需要培训，也不需要示例，而是限制性能。取而代之的是，我们通过学习学习一般和适应性PLM之间的差异来为数据和参数有效适应。通过我们提出的动态低级别重新聚体和学识渊博的体系结构控制器，通过模型权重和子层结构来表示这种差异。实验对话完成，低资源抽象摘要以及多域语言建模的实验显示了通过域自适应预处理进行适应时间和性能的改善。消融表明我们的任务自适应重新聚体化（TARP）和模型搜索（TAMS）组件分别改进了其他参数效率转移（如适配器和结构学习方法），例如学习的稀疏。

在深度学习中，模型通常重用所有输入的相同参数。专家的混合（MOE）违反了这一点，而是为每个传入示例选择不同的参数。结果是一个稀疏激活的模型 - 具有残酷数量的参数 - 但恒定的计算成本。然而，尽管MOE取得了一些显着的成功，但复杂性，沟通成本和培训不稳定的阻碍了广泛的采用 - 我们使用Switch Transformer解决了这些领域。我们简化了MOE路由算法和设计直观的改进模型，以降低的通信和计算成本。我们提出的培训技术有助于纠缠不稳定，我们表明稀疏模型可能首次以较低的精度（BFLOAT16）格式进行培训。我们设计了基于T5基数和T5总数的模型，以使用相同的计算资源获得高达7倍的训练速度。这些改进扩展到多语言设置，我们在所有101种语言中衡量对MT5基本版本的收益。最后，我们通过在“巨大的清洁爬行语料库”上预先培训高达数万亿个参数模型，并在T5-XXL模型上实现4倍的速度，从而提高了语言模型的当前规模。

Large pre-trained language models have been shown to store factual knowledge in their parameters, and achieve state-of-the-art results when fine-tuned on downstream NLP tasks. However, their ability to access and precisely manipulate knowledge is still limited, and hence on knowledge-intensive tasks, their performance lags behind task-specific architectures. Additionally, providing provenance for their decisions and updating their world knowledge remain open research problems. Pre-trained models with a differentiable access mechanism to explicit nonparametric memory can overcome this issue, but have so far been only investigated for extractive downstream tasks. We explore a general-purpose fine-tuning recipe for retrieval-augmented generation (RAG) -models which combine pre-trained parametric and non-parametric memory for language generation. We introduce RAG models where the parametric memory is a pre-trained seq2seq model and the non-parametric memory is a dense vector index of Wikipedia, accessed with a pre-trained neural retriever. We compare two RAG formulations, one which conditions on the same retrieved passages across the whole generated sequence, and another which can use different passages per token. We fine-tune and evaluate our models on a wide range of knowledge-intensive NLP tasks and set the state of the art on three open domain QA tasks, outperforming parametric seq2seq models and task-specific retrieve-and-extract architectures. For language generation tasks, we find that RAG models generate more specific, diverse and factual language than a state-of-the-art parametric-only seq2seq baseline.

我们提出了一种用于在生成答案时将信息与多个检索文件中的信息组合的可检索增强的开放式开放式开放式开放域问题训练方法。我们将检索决策模拟作为相关文件集的潜在变量。由于通过对所检索的文件集的边缘化，因此使用期望最大化算法估计这一点。我们迭代地估计我们的潜在变量的价值（给定问题的这些相关文档集），然后使用此估计来更新检索器和读取器参数。我们假设这种端到端的训练允许训练信号流到读者，然后比上演明智的训练更好地流到猎犬。这导致检索器能够为问题和读者选择更多相关文档，这些文件在更准确的文档中培训以生成答案。三个基准数据集的实验表明，我们所提出的方法优于所有现有的相当大小的方法2-3％绝对精确匹配点，实现了新的最先进的结果。我们的结果还展示了学习检索以改善答复的可行性，而无明确监督检索决策。

通过微调将大规模的预训练语言模型适应下游任务是实现NLP基准测试最先进性能的标准方法。然而，微调具有数百万或数十亿个参数的所有重量模型是对低资源设置中不稳定的采样低效，并且浪费，因为它需要为每个任务存储模型的单独副本。最近的工作已经开发了参数高效的微调方法，但这些方法仍然需要相对大量的参数或表现不足标准微调。在这项工作中，我们提出了一种特殊调整大型语言模型的方法，其在任务性能和比率参数之间具有更好的权衡的方法，而不是比上事先工作。 Compacter通过构建适配器，低级优化和参数化超复分乘法层的思想之上来实现这一目标。具体地，Compacter将特定于特定的权重矩阵插入到预估计模型的权重中，这些权重被有效地计算为共享的“慢速”权重和“快速”等级 - 每个Compacter层定义的矩阵之间的矩阵产品的总和。仅通过培训0.047％的预磨料模型的参数，Compacter会在胶水上标准微调和胜过标准微调的标准微调和低资源设置。我们的代码在〜\ url {https://github.com/rabeehk/compacter}上公开使用。

从有限的资源中获得最大收益可以进步自然语言处理（NLP）研究和实践，同时保守资源。这些资源可能是数据，时间，存储或能源。NLP的最新工作从缩放率产生了有趣的结果。但是，仅使用比例来改善结果意味着资源消耗也会扩展。这种关系激发了对有效方法的研究，这些方法需要更少的资源才能获得相似的结果。这项调查涉及NLP效率的方法和发现，旨在指导该领域的新研究人员并激发新方法的发展。

Transformers have become the state-of-the-art neural network architecture across numerous domains of machine learning. This is partly due to their celebrated ability to transfer and to learn in-context based on few examples. Nevertheless, the mechanisms by which Transformers become in-context learners are not well understood and remain mostly an intuition. Here, we argue that training Transformers on auto-regressive tasks can be closely related to well-known gradient-based meta-learning formulations. We start by providing a simple weight construction that shows the equivalence of data transformations induced by 1) a single linear self-attention layer and by 2) gradient-descent (GD) on a regression loss. Motivated by that construction, we show empirically that when training self-attention-only Transformers on simple regression tasks either the models learned by GD and Transformers show great similarity or, remarkably, the weights found by optimization match the construction. Thus we show how trained Transformers implement gradient descent in their forward pass. This allows us, at least in the domain of regression problems, to mechanistically understand the inner workings of optimized Transformers that learn in-context. Furthermore, we identify how Transformers surpass plain gradient descent by an iterative curvature correction and learn linear models on deep data representations to solve non-linear regression tasks. Finally, we discuss intriguing parallels to a mechanism identified to be crucial for in-context learning termed induction-head (Olsson et al., 2022) and show how it could be understood as a specific case of in-context learning by gradient descent learning within Transformers.

Modern machine learning requires system designers to specify aspects of the learning pipeline, such as losses, architectures, and optimizers. Meta-learning, or learning-to-learn, instead aims to learn those aspects, and promises to unlock greater capabilities with less manual effort. One particularly ambitious goal of meta-learning is to train general-purpose in-context learning algorithms from scratch, using only black-box models with minimal inductive bias. Such a model takes in training data, and produces test-set predictions across a wide range of problems, without any explicit definition of an inference model, training loss, or optimization algorithm. In this paper we show that Transformers and other black-box models can be meta-trained to act as general-purpose in-context learners. We characterize phase transitions between algorithms that generalize, algorithms that memorize, and algorithms that fail to meta-train at all, induced by changes in model size, number of tasks, and meta-optimization. We further show that the capabilities of meta-trained algorithms are bottlenecked by the accessible state size (memory) determining the next prediction, unlike standard models which are thought to be bottlenecked by parameter count. Finally, we propose practical interventions such as biasing the training distribution that improve the meta-training and meta-generalization of general-purpose learning algorithms.

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.

差异化（DP）学习在建立大型文本模型方面的成功有限，并尝试直接将差异化私有随机梯度下降（DP-SGD）应用于NLP任务，从而导致了大量的性能下降和高度计算的开销。我们表明，通过（1）使用大型验证模型可以缓解这种性能下降； （2）适合DP优化的超参数； （3）与训练过程对齐的微调目标。通过正确设定这些因素，我们将获得私人NLP模型，以优于最先进的私人培训方法和强大的非私人基准 - 通过直接对中等大小的Corpora进行DP优化的预审计模型。为了解决使用大型变压器运行DP-SGD的计算挑战，我们提出了一种存储器保存技术，该技术允许DP-SGD中的剪辑在不实例化模型中任何层的每个示例梯度的情况下运行。该技术使私人训练变压器的内存成本几乎与非私人培训相同，并以适度的运行时间开销。与传统的观点相反，即DP优化在学习高维模型（由于尺寸缩放的噪声）方面失败的经验结果表明，使用预审预周化模型的私人学习往往不会遭受维度依赖性性能降低的障碍。