Related works used indexes like CKA and variants of CCA to measure the similarity of cross-lingual representations in multilingual language models. In this paper, we argue that assumptions of CKA/CCA align poorly with one of the motivating goals of cross-lingual learning analysis, i.e., explaining zero-shot cross-lingual transfer. We highlight what valuable aspects of cross-lingual similarity these indexes fail to capture and provide a motivating case study \textit{demonstrating the problem empirically}. Then, we introduce \textit{Average Neuron-Wise Correlation (ANC)} as a straightforward alternative that is exempt from the difficulties of CKA/CCA and is good specifically in a cross-lingual context. Finally, we use ANC to construct evidence that the previously introduced ``first align, then predict'' pattern takes place not only in masked language models (MLMs) but also in multilingual models with \textit{causal language modeling} objectives (CLMs). Moreover, we show that the pattern extends to the \textit{scaled versions} of the MLMs and CLMs (up to 85x original mBERT).\footnote{Our code is publicly available at \url{https://github.com/TartuNLP/xsim}}

低资源语言（例如波罗的海语言）受益于具有非凡的跨语性转移性能功能的大型多语言模型（LMS）。这项工作是对多语言LMS的跨语性表示的解释和分析研究。先前的作品假设这些LMS内部项目表示不同语言的代表形式为共享的跨语言空间。但是，文献产生了矛盾的结果。在本文中，我们重新审视了先前的工作，声称“ Bert不是Interlingua”，并表明不同的语言确实会在此类语言模型中收敛到共享空间，并具有另一种选择策略或相似性索引。然后，我们对使用378个成对语言比较的两个最受欢迎的多语言LMS进行了跨语性代表性分析。我们发现，虽然大多数语言共享联合跨语言空间，但有些语言却没有。但是，我们观察到波罗的海语言确实属于共享空间。

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。

一些基于变压器的模型可以执行跨语言转移学习：这些模型可以通过一种语言对特定任务进行培训，并以另一种语言的同一任务给予相对良好的结果，尽管仅在单语任务中进行了预先培训。但是，关于这些基于变压器的模型是否学习跨语言的通用模式，目前尚无共识。我们提出了一种单词级的任务不可能的方法，以评估此类模型构建的上下文化表示的对齐方式。我们表明，与以前的方法相比，我们的方法提供了更准确的翻译成对，以评估单词级别对齐。我们的结果表明，基于多语言变压器模型的某些内部层优于其他明确对齐的表示，甚至根据多语言对齐的更严格的定义，更是如此。

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。

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.

表明多语言语言模型允许跨脚本和语言进行非平凡的转移。在这项工作中，我们研究了能够转移的内部表示的结构。我们将重点放在性别区分作为实际案例研究的表示上，并研究在跨不同语言的共享子空间中编码性别概念的程度。我们的分析表明，性别表示由几个跨语言共享的重要组成部分以及特定于语言的组成部分组成。与语言无关和特定语言的组成部分的存在为我们做出的有趣的经验观察提供了解释：虽然性别分类跨语言良好地传递了跨语言，对性别删除的干预措施，对单一语言进行了培训，但不会轻易转移给其他人。

Misinformation spread over social media has become an undeniable infodemic. However, not all spreading claims are made equal. If propagated, some claims can be destructive, not only on the individual level, but to organizations and even countries. Detecting claims that should be prioritized for fact-checking is considered the first step to fight against spread of fake news. With training data limited to a handful of languages, developing supervised models to tackle the problem over lower-resource languages is currently infeasible. Therefore, our work aims to investigate whether we can use existing datasets to train models for predicting worthiness of verification of claims in tweets in other languages. We present a systematic comparative study of six approaches for cross-lingual check-worthiness estimation across pairs of five diverse languages with the help of Multilingual BERT (mBERT) model. We run our experiments using a state-of-the-art multilingual Twitter dataset. Our results show that for some language pairs, zero-shot cross-lingual transfer is possible and can perform as good as monolingual models that are trained on the target language. We also show that in some languages, this approach outperforms (or at least is comparable to) state-of-the-art models.

翻译质量估计（QE）是预测机器翻译（MT）输出质量的任务，而无需任何参考。作为MT实际应用中的重要组成部分，这项任务已越来越受到关注。在本文中，我们首先提出了XLMRScore，这是一种基于使用XLM-Roberta（XLMR）模型计算的BertScore的简单无监督的QE方法，同时讨论了使用此方法发生的问题。接下来，我们建议两种减轻问题的方法：用未知令牌和预训练模型的跨语性对准替换未翻译的单词，以表示彼此之间的一致性单词。我们在WMT21 QE共享任务的四个低资源语言对上评估了所提出的方法，以及本文介绍的新的英语FARSI测试数据集。实验表明，我们的方法可以在两个零射击方案的监督基线中获得可比的结果，即皮尔森相关性的差异少于0.01，同时在所有低资源语言对中的平均低资源语言对中的无人看管竞争对手的平均水平超过8％的平均水平超过8％。 。

在过去几年中，已经提出了多语言预训练的语言模型（PLMS）的激增，以实现许多交叉曲线下游任务的最先进的性能。但是，了解为什么多语言PLMS表现良好仍然是一个开放域。例如，目前尚不清楚多语言PLM是否揭示了不同语言的一致令牌归因。要解决此问题，请在本文中提出了令牌归因（CCTA）评估框架的交叉致新一致性。三个下游任务中的广泛实验表明，多语言PLMS为多语素同义词分配了显着不同的归因。此外，我们有以下观察结果：1）当它用于培训PLMS时，西班牙语在不同语言中实现了最常见的令牌归属;2）令牌归属的一致性与下游任务中的性能强烈相关。

Pre-trained multilingual language models show significant performance gains for zero-shot cross-lingual model transfer on a wide range of natural language understanding (NLU) tasks. Previously, for zero-shot cross-lingual evaluation, pre-trained models are only fine-tuned on English data and tested on a variety of target languages. In this paper, we do cross-lingual evaluation on various NLU tasks (sentence classification, sequence labeling, question answering) using prompt-tuning and compare it with fine-tuning. The results show that prompt tuning achieves much better cross-lingual transfer than fine-tuning across datasets, with only 0.1% to 0.3% tuned parameters. Additionally, we demonstrate through the analysis that prompt tuning can have better cross-lingual transferability of representations on downstream tasks with better aligned decision boundaries.

In this paper, we show that Multilingual BERT (M-BERT), released by Devlin et al. (2019) as a single language model pre-trained from monolingual corpora in 104 languages, is surprisingly good at zero-shot cross-lingual model transfer, in which task-specific annotations in one language are used to fine-tune the model for evaluation in another language. To understand why, we present a large number of probing experiments, showing that transfer is possible even to languages in different scripts, that transfer works best between typologically similar languages, that monolingual corpora can train models for code-switching, and that the model can find translation pairs. From these results, we can conclude that M-BERT does create multilingual representations, but that these representations exhibit systematic deficiencies affecting certain language pairs.

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。

本文涉及捷克，英语和法语语言的跨语言分析。我们使用五个线性转换与LSTM和CNN基于CNN的分类器进行零射击跨语性分类。我们比较了单个转换的性能，此外，我们与现有的类似伯特的模型面对基于转换的方法。我们表明，与单语言分类不同的是，来自目标域的预训练的嵌入对于改善跨语性分类结果至关重要，在单语分类中，效果并非如此独特。

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.

在本文中，我们建议将不同语言的句子表示对齐到统一的嵌入空间，其中可以用简单的点产品计算语义相似之处（交叉语言和单晶）。预先接受的语言模型与翻译排名任务进行微调。现有工作（Feng等人，2020）使用与批量相同的句子作为否定，这可能会遭受易于否定的问题。我们适应MOCO（赫尔，2020）以进一步提高对准质量。作为实验结果表明，我们的模型产生的句子表示在包括Tatoeba en-Zh的许多任务中实现了新的最先进的，包括STATOEBA EN-ZH类似性搜索（Artetxe和Schwenk，2019b），Bucc en-Zh Bitext Mining，7个数据集上的语义文本相似性。

Multi-lingual language models (LM), such as mBERT, XLM-R, mT5, mBART, have been remarkably successful in enabling natural language tasks in low-resource languages through cross-lingual transfer from high-resource ones. In this work, we try to better understand how such models, specifically mT5, transfer *any* linguistic and semantic knowledge across languages, even though no explicit cross-lingual signals are provided during pre-training. Rather, only unannotated texts from each language are presented to the model separately and independently of one another, and the model appears to implicitly learn cross-lingual connections. This raises several questions that motivate our study, such as: Are the cross-lingual connections between every language pair equally strong? What properties of source and target language impact the strength of cross-lingual transfer? Can we quantify the impact of those properties on the cross-lingual transfer? In our investigation, we analyze a pre-trained mT5 to discover the attributes of cross-lingual connections learned by the model. Through a statistical interpretation framework over 90 language pairs across three tasks, we show that transfer performance can be modeled by a few linguistic and data-derived features. These observations enable us to interpret cross-lingual understanding of the mT5 model. Through these observations, one can favorably choose the best source language for a task, and can anticipate its training data demands. A key finding of this work is that similarity of syntax, morphology and phonology are good predictors of cross-lingual transfer, significantly more than just the lexical similarity of languages. For a given language, we are able to predict zero-shot performance, that increases on a logarithmic scale with the number of few-shot target language data points.

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.

在这项工作中，我们提出了一个系统的实证研究，专注于最先进的多语言编码器在跨越多种不同语言对的交叉语言文档和句子检索任务的适用性。我们首先将这些模型视为多语言文本编码器，并在无监督的ad-hoc句子和文档级CLIR中基准性能。与监督语言理解相比，我们的结果表明，对于无监督的文档级CLIR - 一个没有针对IR特定的微调 - 预训练的多语言编码器的相关性判断，平均未能基于CLWE显着优于早期模型。对于句子级检索，我们确实获得了最先进的性能：然而，通过多语言编码器来满足高峰分数，这些编码器已经进一步专注于监督的时尚，以便句子理解任务，而不是使用他们的香草'现货'变体。在这些结果之后，我们介绍了文档级CLIR的本地化相关性匹配，在那里我们独立地对文件部分进行了查询。在第二部分中，我们评估了在一系列零拍语言和域转移CLIR实验中的英语相关数据中进行微调的微调编码器精细调整的微调我们的结果表明，监督重新排名很少提高多语言变压器作为无监督的基数。最后，只有在域名对比度微调（即，同一域名，只有语言转移），我们设法提高排名质量。我们在目标语言中单次检索的交叉定向检索结果和结果（零拍摄）交叉传输之间的显着实证差异，这指出了在单机数据上训练的检索模型的“单声道过度装备”。

跨语言嵌入（CLWE）已被证明在许多跨语性任务中有用。但是，大多数现有的学习Clwe的方法，包括具有上下文嵌入的方法是无知的。在这项工作中，我们提出了一个新颖的框架，以通过仅利用双语词典的跨语性信号来使上下文嵌入在感觉层面上。我们通过首先提出一种新颖的感知感知的跨熵损失来明确地提出一种新颖的感知跨熵损失来实现我们的框架。通过感知感知的跨熵损失预算的单语Elmo和BERT模型显示出对单词感官歧义任务的显着改善。然后，我们提出了一个感官对齐目标，除了跨语义模型预训练的感知感知跨熵损失以及几种语言对的跨语义模型（英语对德语/西班牙语/日本/中文）。与最佳的基线结果相比，我们的跨语言模型分别在零摄影，情感分类和XNLI任务上达到0.52％，2.09％和1.29％的平均绩效提高。