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masakhane-reading-group's Issues

[08/07/2020] 5:15PM GMT+1 : ELECTRA - PRE-TRAINING TEXT ENCODERS AS DISCRIMINATORS RATHER THAN GENERATORS

Link - https://arxiv.org/pdf/2003.10555.pdf

Masked language modeling (MLM) pre-training methods such as BERT corrupt the input by replacing some tokens with [MASK] and then train a model to reconstruct the original tokens. While they produce good results when transferred to downstream NLP tasks, they generally require large amounts of compute to be effective. As an alternative, we propose a more sample-efficient pre-training task called replaced token detection. Instead of masking the input, our approach corrupts it by replacing some tokens with plausible alternatives sampled from a small generator network. Then, instead of training a model that predicts the original identities of the corrupted tokens, we train a discriminative model that predicts whether each token in the corrupted input was replaced by a generator sample or not. Thorough experiments demonstrate this new pre-training task is more efficient than MLM because the task is defined over all input tokens rather than just the small subset that was masked out. As a result, the contextual representations learned by our approach substantially outperform the ones learned by BERT given the same model size, data, and compute. The gains are particularly strong for small models; for example, we train a model on one GPU for 4 days that outperforms GPT (trained using 30x more compute) on the GLUE natural language understanding benchmark. Our approach also works well at scale, where it performs comparably to RoBERTa and XLNet while using less than 1/4 of their compute and outperforms them when using the same amount of compute.

Speech Paper Voting Round 2

In this issue you can either:

• Add papers that you think are interesting to read and discuss (please stick to the format).
• Vote: should be done using 👍 on comments

Example: Voting Paper #1

I have added some papers collected on the Papers to read sheet

[02/07/2020] 5:15PM GMT+1 : ELECTRA - PRE-TRAINING TEXT ENCODERS AS DISCRIMINATORS RATHER THAN GENERATORS

Link - https://arxiv.org/pdf/2003.10555.pdf

Masked language modeling (MLM) pre-training methods such as BERT corrupt the input by replacing some tokens with [MASK] and then train a model to reconstruct the original tokens. While they produce good results when transferred to downstream NLP tasks, they generally require large amounts of compute to be effective. As an alternative, we propose a more sample-efficient pre-training task called replaced token detection. Instead of masking the input, our approach corrupts it by replacing some tokens with plausible alternatives sampled from a small generator network. Then, instead of training a model that predicts the original identities of the corrupted tokens, we train a discriminative model that predicts whether each token in the corrupted input was replaced by a generator sample or not. Thorough experiments demonstrate this new pre-training task is more efficient than MLM because the task is defined over all input tokens rather than just the small subset that was masked out. As a result, the contextual representations learned by our approach substantially outperform the ones learned by BERT given the same model size, data, and compute. The gains are particularly strong for small models; for example, we train a model on one GPU for 4 days that outperforms GPT (trained using 30x more compute) on the GLUE natural language understanding benchmark. Our approach also works well at scale, where it performs comparably to RoBERTa and XLNet while using less than 1/4 of their compute and outperforms them when using the same amount of compute.

[28/05/2020] 5:15PM GMT+1 : Making Monolingual Sentence Embeddings Multilingual using Knowledge Distillation

Summary:

We present an easy and efficient method to extend existing sentence embedding models to new languages. This allows to create multilingual versions from previously monolingual models. The training is based on the idea that a translated sentence should be mapped to the same location in the vector space as the original sentence. We use the original (monolingual) model to generate sentence embeddings for the source language and then train a new system on translated sentences to mimic the original model. Compared to other methods for training multilingual sentence embeddings, this approach has several advantages: It is easy to extend existing models with relatively few samples to new languages, it is easier to ensure desired properties for the vector space, and the hardware requirements for training is lower. We demonstrate the effectiveness of our approach for 10 languages from various language families. Code to extend sentence embeddings models to more than 400 languages is publicly available.

Word Translation Without Parallel Data

https://arxiv.org/abs/1710.04087

Short Description:

State-of-the-art methods for learning cross-lingual word embeddings have relied on bilingual dictionaries or parallel corpora. Recent studies showed that the need for parallel data supervision can be alleviated with character-level information. While these methods showed encouraging results, they are not on par with their supervised counterparts and are limited to pairs of languages sharing a common alphabet. In this work, we show that we can build a bilingual dictionary between two languages without using any parallel corpora, by aligning monolingual word embedding spaces in an unsupervised way. Without using any character information, our model even outperforms existing supervised methods on cross-lingual tasks for some language pairs. Our experiments demonstrate that our method works very well also for distant language pairs, like English-Russian or English-Chinese. We finally describe experiments on the English-Esperanto low-resource language pair, on which there only exists a limited amount of parallel data, to show the potential impact of our method in fully unsupervised machine translation. Our code, embeddings and dictionaries are publicly available.

[14/05/2020] 5:15PM GMT+1 Transfer Learning for Low-Resource Neural Machine Translation

Link - https://www.isi.edu/natural-language/mt/emnlp16-transfer.pdf

Summary:

The authors perform transfer learning for low-resourced NMT via a method that has to stages: first train a high-resource language pair (the parent model), then transfer some of the learned parameters to the low-resource pair (the child model) to initialize and constrain training. They observe improvements in BLEU scores. Also, they apply this transfer learning method to syntax-based MT and obtain improvements.

Papers Voting

In this issue you can either:

• Add papers that you think are interesting to read and discuss (please stick to the format).
• vote: should be done using 👍 on comments

Example: hadyelsahar#1

[21/05/2020] 5:15PM GMT+1 : MultiFiT: Efficient Multi-lingual Language Model Fine-tuning

Link: https://www.aclweb.org/anthology/D19-1572.pdf

Short Description:

The authors propose Multi-lingual language model Fine-Tuning (MultiFiT) to enable people to train and fine-tune language models efficiently on their languages, particularly low-resourced ones. They also introduce a zero-shot method for existing pretrained models.

[18/06/2020] 5:15PM GMT+1 : Neural Network Language Models for Low Resource Languages

For resource rich languages, recent works have shown Neural Network based Language Models (NNLMs) to be an effective modeling technique for Automatic Speech Recognition, out performing standard n-gram language models (LMs). For low resource languages, however, the performance of NNLMs has not been well explored. In this paper, we evaluate the effectiveness of NNLMs for low resource languages and show that NNLMs learn better word probabilities than state-of-theart n-gram models even when the amount of training data is severely limited. We show that interpolated NNLMs obtain a lower WER than standard n-gram models, no mater the amount of training data. Additionally, we observe that with small amounts of data (approx. 100k training tokens), feed-forward NNLMs obtain lower perplexity than recurrent NNLMs, while for the larger data condition (500k-1M training tokens), recurrent NNLMs can obtain lower perplexity than feed-forward models.

Decolonial AI: Decolonial Theory as Sociotechnical Foresight in Artificial Intelligence

https://arxiv.org/pdf/2007.04068.pdf

Summary:
This paper explores the important role of critical science, and in particular of post-colonial and decolonial theories, in understanding and shaping the ongoing advances in artificial intelligence. Artificial Intelligence (AI) is viewed as amongst the technological advances that will reshape modern societies and their relations. Whilst the design and deployment of systems that continually adapt holds the promise of far-reaching positive change, they simultaneously pose significant risks, especially to already vulnerable peoples. Values and power are central to this discussion. Decolonial theories use historical hindsight to explain patterns of power that shape our intellectual, political, economic, and social world. By embedding a decolonial critical approach within its technical practice, AI communities can develop foresight and tactics that can better align research and technology development with established ethical principles, centring vulnerable peoples who continue to bear the brunt of negative impacts of innovation and scientific progress. We highlight problematic applications that are instances of coloniality, and using a decolonial lens, submit three tactics that can form a decolonial field of artificial intelligence: creating a critical technical practice of AI, seeking reverse tutelage and reverse pedagogies, and the renewal of affective and political communities. The years ahead will usher in a wave of new scientific breakthroughs and technologies driven by AI research, making it incumbent upon AI communities to strengthen the social contract through ethical foresight and the multiplicity of intellectual perspectives available to us; ultimately supporting future technologies that enable greater well-being, with the goal of beneficence and justice for all.

[11/06/2020] 5:15PM GMT+1 : Massively Multilingual Neural Machine Translation in the Wild: Findings and Challenges

Link - https://arxiv.org/pdf/1907.05019.pdf

Short description:
We introduce our efforts towards building a universal neural machine translation (NMT) system capable of translating between any language pair. We set a milestone towards this goal by building a single massively multilingual NMT model handling 103 languages trained on over 25 billion examples. Our system demonstrates effective transfer learning ability, significantly improving translation quality of low-resource languages, while keeping high-resource language translation quality on-par with competitive bilingual baselines. We provide indepth analysis of various aspects of model building that are crucial to achieving quality and practicality in universal NMT. While we prototype a high-quality universal translation system, our extensive empirical analysis exposes issues that need to be further addressed, and we suggest directions for future research.

[04/06/2020] 5:15PM GMT+1 : It’s Easier to Translate out of English than into it: Measuring Neural Translation Difficulty by Cross-Mutual Information

Link - https://arxiv.org/abs/2005.02354

Abstract:
The performance of neural machine translation systems is commonly evaluated in terms of BLEU. However, due to its reliance on target language properties and generation, the BLEU metric does not allow an assessment of which translation directions are more difficult to model. In this paper, we propose cross-mutual information (XMI): an asymmetric information-theoretic metric of machine translation difficulty that exploits the probabilistic nature of most neural machine translation models. XMI allows us to better evaluate the difficulty of translating text into the target language while controlling for the difficulty of the target-side generation component independent of the translation task. We then present the first systematic and controlled study of cross-lingual translation difficulties using modern neural translation systems