While prior work has established that the use of parallel data is conducive for cross-lingual learning, it is unclear if the improvements come from the data itself, or if it is the modeling of parallel interactions that matters. Exploring this, we examine the usage of unsupervised machine translation to generate synthetic parallel data, and compare it to supervised machine translation and gold parallel data. We find that even model generated parallel data can be useful for downstream tasks, in both a general setting (continued pretraining) as well as the task-specific setting (translate-train), although our best results are still obtained using real parallel data. Our findings suggest that existing multilingual models do not exploit the full potential of monolingual data, and prompt the community to reconsider the traditional categorization of cross-lingual learning approaches.

在多语言甚至单语言中鉴定的模型的零拍跨语言能力刺激了许多假设，以解释这一有趣的经验结果。但是，由于预处理的成本，大多数研究都使用公共模型的公共模型，其预处理方法（例如代币化，语料库规模和计算预算的选择）可能会大不相同。当研究人员对自己的模型预识时，他们通常会在预算有限的情况下这样做，并且与SOTA模型相比，最终的模型的表现可能明显不足。这些实验差异导致有关这些模型跨语性能力的性质的各种不一致的结论。为了帮助对该主题进行进一步研究，我们发布了10个单语字节级模型，并在相同的配置下进行了严格审慎的概述，并具有大型计算预算（相当于V100的420天）和Corpora，比原始BERT大4倍。由于它们不含令牌，因此消除了看不见的令牌嵌入的问题，从而使研究人员可以在具有不同脚本的语言中尝试更广泛的跨语言实验。此外，我们释放了在不自然语言文本上预测的两个模型，这些模型可用于理智检查实验。关于质量检查和NLI任务的实验表明，我们的单语模型实现了多语言的竞争性能，因此可以加强我们对语言模型中跨语性可传递性的理解。

Much recent progress in applications of machine learning models to NLP has been driven by benchmarks that evaluate models across a wide variety of tasks. However, these broad-coverage benchmarks have been mostly limited to English, and despite an increasing interest in multilingual models, a benchmark that enables the comprehensive evaluation of such methods on a diverse range of languages and tasks is still missing. To this end, we introduce the Cross-lingual TRansfer Evaluation of Multilingual Encoders (XTREME) benchmark, a multi-task benchmark for evaluating the cross-lingual generalization capabilities of multilingual representations across 40 languages and 9 tasks. We demonstrate that while models tested on English reach human performance on many tasks, there is still a sizable gap in the performance of cross-lingually transferred models, particularly on syntactic and sentence retrieval tasks. There is also a wide spread of results across languages. We release the benchmark 1 to encourage research on cross-lingual learning methods that transfer linguistic knowledge across a diverse and representative set of languages and tasks.

对于多语言序列到序列预审预周序模型（多语言SEQ2SEQ PLM），例如姆巴特（Mbart），自制的预处理任务接受了多种单语言的培训，例如25种来自CommonCrawl的语言，而下游的跨语言任务通常在双语语言子集上进行，例如英语 - 德国人，存在数据差异，即领域的差异，以及跨语言学习客观差异，即在训练和填充阶段之间的任务差异。为了弥合上述跨语言域和任务差距，我们将使用额外的代码切换恢复任务扩展了香草预后管道。具体而言，第一阶段采用自我监督的代码转换还原任务作为借口任务，从而允许多语言SEQ2SEQ PLM获取一些域内对齐信息。在第二阶段，我们正常在下游数据上微调模型。 NLG评估（12个双语翻译任务，30个零射击任务和2项跨语言摘要任务）和NLU评估（7个跨语性自然语言推理任务）的实验表明，我们的模型超过了强大的基线MBART，具有标准的FINETUNNING，这表明了我们的模型策略，一致。分析表明，我们的方法可以缩小跨语性句子表示的欧几里得距离，并通过微不足道的计算成本改善模型概括。我们在：https：//github.com/zanchangtong/csr4mbart上发布代码。

与辅助语言的元学习已经表明了对交叉语言自然语言处理的有希望的改进。然而，以前的研究采样使用相同语言的元培训和元测试数据，这限制了模型交叉传输的能力。在本文中，我们提出了XLA-MAML，在元学习阶段执行直接交叉调整。我们对自然语言推理和问题进行零射击和几次拍摄实验。实验结果表明了我们在不同语言，任务和预磨料模型中的方法的有效性。我们还对元学习的各种交叉特定设置进行了分析，包括采样策略和并行性。

我们提出了一种两阶段的培训方法，用于开发单个NMT模型，以翻译英语和英语的看不见的语言。对于第一阶段，我们将编码器模型初始化以鉴定XLM-R和Roberta的权重，然后对25种语言的平行数据进行多种语言微调。我们发现该模型可以推广到对看不见的语言的零击翻译。在第二阶段，我们利用这种概括能力从单语数据集生成合成的并行数据，然后用连续的反向翻译训练。最终模型扩展到了英语到许多方向，同时保持了多到英语的性能。我们称我们的方法为ecxtra（以英语为中心的跨语言（x）转移）。我们的方法依次利用辅助并行数据和单语言数据，并且在概念上很简单，仅在两个阶段都使用标准的跨熵目标。最终的ECXTRA模型对8种低资源语言的无监督NMT进行了评估，该语言为英语至哈萨克语（22.3> 10.4 bleu）以及其他15个翻译方向的竞争性能而获得了新的最先进。

Universal cross-lingual sentence embeddings map semantically similar cross-lingual sentences into a shared embedding space. Aligning cross-lingual sentence embeddings usually requires supervised cross-lingual parallel sentences. In this work, we propose mSimCSE, which extends SimCSE to multilingual settings and reveal that contrastive learning on English data can surprisingly learn high-quality universal cross-lingual sentence embeddings without any parallel data. In unsupervised and weakly supervised settings, mSimCSE significantly improves previous sentence embedding methods on cross-lingual retrieval and multilingual STS tasks. The performance of unsupervised mSimCSE is comparable to fully supervised methods in retrieving low-resource languages and multilingual STS. The performance can be further enhanced when cross-lingual NLI data is available. Our code is publicly available at https://github.com/yaushian/mSimCSE.

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。

在本文中，我们介绍了DOCMT5，这是一种预先培训的多语言序列到序列语言模型，具有大规模并行文档。虽然以前的方法专注于利用句子级并行数据，但我们尝试构建一个可以理解和生成长文件的通用预训练模型。我们提出了一个简单有效的预训练目标 - 文件重新排序机翻译（DRMT），其中需要翻译和屏蔽的输入文件。 DRMT在各种文档级生成任务中对强大基线带来一致的改进，包括超过12个BLEU积分，用于观看语言对文件级MT，超过7个BLEU积分，用于看不见的语言对文件级MT和3胭脂-1位为言语对交叉术概要。我们在WMT20 De-en和IWSLT15 Zh-ZH文档翻译任务中实现了最先进的（SOTA）。我们还对文档预培训的各种因素进行了广泛的分析，包括（1）预培训数据质量的影响和（2）组合单语言和交叉训练的影响。我们计划公开使用我们的模型检查站。

Translating training data into many languages has emerged as a practical solution for improving cross-lingual transfer. For tasks that involve span-level annotations, such as information extraction or question answering, an additional label projection step is required to map annotated spans onto the translated texts. Recently, a few efforts have utilized a simple mark-then-translate method to jointly perform translation and projection by inserting special markers around the labeled spans in the original sentence. However, as far as we are aware, no empirical analysis has been conducted on how this approach compares to traditional annotation projection based on word alignment. In this paper, we present an extensive empirical study across 42 languages and three tasks (QA, NER, and Event Extraction) to evaluate the effectiveness and limitations of both methods, filling an important gap in the literature. Experimental results show that our optimized version of mark-then-translate, which we call EasyProject, is easily applied to many languages and works surprisingly well, outperforming the more complex word alignment-based methods. We analyze several key factors that affect end-task performance, and show EasyProject works well because it can accurately preserve label span boundaries after translation. We will publicly release all our code and data.

This paper demonstrates that multilingual denoising pre-training produces significant performance gains across a wide variety of machine translation (MT) tasks. We present mBART -a sequence-to-sequence denoising auto-encoder pre-trained on large-scale monolingual corpora in many languages using the BART objective . mBART is the first method for pre-training a complete sequence-to-sequence model by denoising full texts in multiple languages, while previous approaches have focused only on the encoder, decoder, or reconstructing parts of the text. Pre-training a complete model allows it to be directly fine tuned for supervised (both sentence-level and document-level) and unsupervised machine translation, with no task-specific modifications. We demonstrate that adding mBART initialization produces performance gains in all but the highest-resource settings, including up to 12 BLEU points for low resource MT and over 5 BLEU points for many document-level and unsupervised models. We also show it also enables new types of transfer to language pairs with no bi-text or that were not in the pre-training corpus, and present extensive analysis of which factors contribute the most to effective pre-training.

Cross-lingual transfer learning without labeled target language data or parallel text has been surprisingly effective in zero-shot cross-lingual classification, question answering, unsupervised machine translation, etc. However, some recent publications have claimed that domain mismatch prevents cross-lingual transfer, and their results show that unsupervised bilingual lexicon induction (UBLI) and unsupervised neural machine translation (UNMT) do not work well when the underlying monolingual corpora come from different domains (e.g., French text from Wikipedia but English text from UN proceedings). In this work, we show that a simple initialization regimen can overcome much of the effect of domain mismatch in cross-lingual transfer. We pre-train word and contextual embeddings on the concatenated domain-mismatched corpora, and use these as initializations for three tasks: MUSE UBLI, UN Parallel UNMT, and the SemEval 2017 cross-lingual word similarity task. In all cases, our results challenge the conclusions of prior work by showing that proper initialization can recover a large portion of the losses incurred by domain mismatch.

以前的工作主要侧重于改善NLU任务的交叉传输，具有多语言预用编码器（MPE），或提高与伯特的监督机器翻译的性能。然而，探索了，MPE是否可以有助于促进NMT模型的交叉传递性。在本文中，我们专注于NMT中的零射频转移任务。在此任务中，NMT模型培训，只有一个语言对的并行数据集和搁置架MPE，然后它直接测试在零拍语言对上。我们为此任务提出了Sixt，一个简单而有效的模型。 SIXT利用了两阶段培训计划利用MPE，并进一步改进了解离编码器和容量增强的解码器。使用此方法，SIMPT显着优于MBart，这是一个用于NMT的预磨削的多语言编码器解码器模型，平均改善了14个源语言的零拍摄的任何英语测试集上的7.1 BLEU。此外，培训计算成本和培训数据较少，我们的模型在15个任何英语测试组上实现了比Criss和M2M-100，两个强大的多语言NMT基线更好的性能。

Prior work has shown that it is possible to expand pretrained Masked Language Models (MLMs) to new languages by learning a new set of embeddings, while keeping the transformer body frozen. Despite learning a small subset of parameters, this approach is not compute-efficient, as training the new embeddings requires a full forward and backward pass over the entire model. In this work, we propose mini-model adaptation, a compute-efficient alternative that builds a shallow mini-model from a fraction of a large model's parameters. New language-specific embeddings can then be efficiently trained over the mini-model, and plugged into the aligned large model for rapid cross-lingual transfer. We explore two approaches to learn mini-models: MiniJoint, which jointly pretrains the primary model and the mini-model using a single transformer with a secondary MLM head at a middle layer; and MiniPost, where we start from a regular pretrained model and build a mini-model by extracting and freezing a few layers and learning a small number of parameters on top. Experiments on XNLI, MLQA and PAWS-X show that mini-model adaptation matches the performance of the standard approach using up to 2.4x less compute.

我们描述了JD Explore Academy对WMT 2022共享的一般翻译任务的提交。我们参加了所有高资源曲目和一条中型曲目，包括中文英语，德语英语，捷克语英语，俄语 - 英语和日语英语。我们通过扩大两个主要因素，即语言对和模型大小，即\ textbf {vega-mt}系统来推动以前的工作的极限 - 进行翻译的双向培训。至于语言对，我们将“双向”扩展到“多向”设置，涵盖所有参与语言，以利用跨语言的常识，并将其转移到下游双语任务中。至于型号尺寸，我们将变压器限制到拥有近47亿参数的极大模型，以完全增强我们VEGA-MT的模型容量。此外，我们采用数据增强策略，例如单语数据的循环翻译以及双语和单语数据的双向自我训练，以全面利用双语和单语言数据。为了使我们的Vega-MT适应通用域测试集，设计了概括调整。根据受约束系统的官方自动分数，根据图1所示的sacrebleu，我们在{zh-en（33.5），en-zh（49.7）（49.7），de-en（33.7）上获得了第一名-de（37.8），CS-EN（54.9），En-CS（41.4）和En-Ru（32.7）}，在{ru-en（45.1）和Ja-en（25.6）}和第三名上的第二名和第三名在{en-ja（41.5）}上； W.R.T彗星，我们在{zh-en（45.1），en-zh（61.7），de-en（58.0），en-de（63.2），cs-en（74.7），ru-en（ru-en（ru-en）上，我们获得了第一名64.9），en-ru（69.6）和en-ja（65.1）}，分别在{en-cs（95.3）和ja-en（40.6）}上的第二名。将发布模型，以通过GitHub和Omniforce平台来促进MT社区。

在所有人类语言对之间实现通用翻译是机器翻译的圣杯（MT）研究。虽然最近在大量的多语言MT中的进展是达到这一目标的一步，但它变得明显，即简单地通过在更加平行数据上训练扩展多语言MT系统是不可编译的，因为用于低资源和非英语的标记数据的可用性 - 姓氏对禁止有限。为此，我们展示了一种务实的方法，可以使用监督和自我监督目标的混合来构建涵盖数百种语言的多语种MT模型，具体取决于不同语言对的数据可用性。我们展示这两种训练范例之间的协同作用使模型能够在零资源设置中产生高质量的翻译，甚至超过监控的用于中资和中资和中资质。我们开展广泛的实验，了解多语言监督，域错配和平行和单机数据量的效果，以了解我们自我监督的多语言模型的质量。为了展示方法的可扩展性，我们培训具有200多种语言的模型，并在几个先前研究的语言上展示了对零资源翻译的高性能。我们希望我们的调查结果将成为踏脚石，以便为下一千种语言进行翻译。

虽然最近关于多语种语言模型的工作已经证明了他们对下游任务的交叉零射击传输的能力，但社区缺乏符合语言之间的共享属性，可以实现这种转移。涉及成对的自然语言的分析通常是不确定的，并且矛盾以来，许多语言方面同时不同。在本文中，我们进行大规模的实证研究，通过测量四种不同的自然语言和通过修改脚本，单词顺序和语法等方面构造的零拍摄传递来隔离各种语言特性的影响。在其他事情之外，我们的实验表明，当语言的单词顺序不同时，缺乏子字重叠显着影响零拍摄传输，并且在语言之间的传输性能和Word嵌入对准之间存在强烈相关性（例如，r = 0.94关于NLI的任务）。我们的结果呼吁专注于在明确改进语言之间的嵌入对齐而不是依赖于隐含的出现。

我们对真正低资源语言的神经机翻译（NMT）进行了实证研究，并提出了一个训练课程，适用于缺乏并行培训数据和计算资源的情况，反映了世界上大多数世界语言和研究人员的现实致力于这些语言。以前，已经向低资源语言储存了使用后翻译（BT）和自动编码（AE）任务的无监督NMT。我们证明利用可比的数据和代码切换作为弱监管，与BT和AE目标相结合，即使仅使用适度的计算资源，低资源语言也会显着改进。在这项工作中提出的培训课程实现了Bleu分数，可通过+12.2 Bleu为古吉拉特和+3.7 Bleu为哈萨克斯培训的监督NMT培训，展示了弱势监督的巨大监督态度资源语言。在受到监督数据的培训时，我们的培训课程达到了索马里数据集（索马里29.3的BLEU的最先进的结果）。我们还观察到增加更多时间和GPU来培训可以进一步提高性能，强调报告在MT研究中的报告资源使用的重要性。

State-of-the-art natural language processing systems rely on supervision in the form of annotated data to learn competent models. These models are generally trained on data in a single language (usually English), and cannot be directly used beyond that language. Since collecting data in every language is not realistic, there has been a growing interest in crosslingual language understanding (XLU) and low-resource cross-language transfer. In this work, we construct an evaluation set for XLU by extending the development and test sets of the Multi-Genre Natural Language Inference Corpus (MultiNLI) to 15 languages, including low-resource languages such as Swahili and Urdu. We hope that our dataset, dubbed XNLI, will catalyze research in cross-lingual sentence understanding by providing an informative standard evaluation task. In addition, we provide several baselines for multilingual sentence understanding, including two based on machine translation systems, and two that use parallel data to train aligned multilingual bag-of-words and LSTM encoders. We find that XNLI represents a practical and challenging evaluation suite, and that directly translating the test data yields the best performance among available baselines.

一种有效的横向传输方法是在一种语言中微调在监督数据集上的双语或多语言模型，并以零拍方式在另一种语言上进行评估。在培训时间或推理时间翻译例子也是可行的替代方案。然而，存在与文献中很少有关的这些方法相关的成本。在这项工作中，我们在其有效性（例如，准确性），开发和部署成本方面分析交叉语言方法，以及推理时间的延迟。我们的三个任务的实验表明最好的交叉方法是高度任务依赖性的。最后，通过结合零射和翻译方法，我们在这项工作中使用的三个数据集中实现了最先进的。基于这些结果，我们对目标语言手动标记的培训数据有所了解。代码和翻译的数据集可在https://github.com/unicamp-dl/cross-lingsual-analysis上获得