Arij Riabi


2022

pdf
Fine-tuning and Sampling Strategies for Multimodal Role Labeling of Entities under Class Imbalance
Syrielle Montariol | Étienne Simon | Arij Riabi | Djamé Seddah
Proceedings of the Workshop on Combating Online Hostile Posts in Regional Languages during Emergency Situations

We propose our solution to the multimodal semantic role labeling task from the CONSTRAINT’22 workshop. The task aims at classifying entities in memes into classes such as “hero” and “villain”. We use several pre-trained multi-modal models to jointly encode the text and image of the memes, and implement three systems to classify the role of the entities. We propose dynamic sampling strategies to tackle the issue of class imbalance. Finally, we perform qualitative analysis on the representations of the entities.

pdf
Tâches Auxiliaires Multilingues pour le Transfert de Modèles de Détection de Discours Haineux (Multilingual Auxiliary Tasks for Zero-Shot Cross-Lingual Transfer of Hate Speech Detection)
Arij Riabi | Syrielle Montariol | Djamé Seddah
Actes de la 29e Conférence sur le Traitement Automatique des Langues Naturelles. Volume 1 : conférence principale

La tâche de détection de contenus haineux est ardue, car elle nécessite des connaissances culturelles et contextuelles approfondies ; les connaissances nécessaires varient, entre autres, selon la langue du locateur ou la cible du contenu. Or, des données annotées pour des domaines et des langues spécifiques sont souvent absentes ou limitées. C’est là que les données dans d’autres langues peuvent être exploitées ; mais du fait de ces variations, le transfert cross-lingue est souvent difficile. Dans cet article, nous mettons en évidence cette limitation pour plusieurs domaines et langues et montrons l’impact positif de l’apprentissage de tâches auxiliaires multilingues - analyse de sentiments, reconnaissance des entités nommées et tâches reposant sur des informations morpho-syntaxiques - sur le transfert cross-lingue zéro-shot des modèles de détection de discours haineux, afin de combler ce fossé culturel.

pdf
Multilingual Auxiliary Tasks Training: Bridging the Gap between Languages for Zero-Shot Transfer of Hate Speech Detection Models
Syrielle Montariol | Arij Riabi | Djamé Seddah
Findings of the Association for Computational Linguistics: AACL-IJCNLP 2022

Zero-shot cross-lingual transfer learning has been shown to be highly challenging for tasks involving a lot of linguistic specificities or when a cultural gap is present between lan- guages, such as in hate speech detection. In this paper, we highlight this limitation for hate speech detection in several domains and languages using strict experimental settings. Then, we propose to train on multilingual auxiliary tasks – sentiment analysis, named entity recognition, and tasks relying on syntactic information – to improve zero-shot transfer of hate speech detection models across languages. We show how hate speech detection models benefit from a cross-lingual knowledge proxy brought by auxiliary tasks fine-tuning and highlight these tasks’ positive impact on bridging the hate speech linguistic and cultural gap between languages.

2021

pdf
Can Character-based Language Models Improve Downstream Task Performances In Low-Resource And Noisy Language Scenarios?
Arij Riabi | Benoît Sagot | Djamé Seddah
Proceedings of the Seventh Workshop on Noisy User-generated Text (W-NUT 2021)

Recent impressive improvements in NLP, largely based on the success of contextual neural language models, have been mostly demonstrated on at most a couple dozen high- resource languages. Building language mod- els and, more generally, NLP systems for non- standardized and low-resource languages remains a challenging task. In this work, we fo- cus on North-African colloquial dialectal Arabic written using an extension of the Latin script, called NArabizi, found mostly on social media and messaging communication. In this low-resource scenario with data display- ing a high level of variability, we compare the downstream performance of a character-based language model on part-of-speech tagging and dependency parsing to that of monolingual and multilingual models. We show that a character-based model trained on only 99k sentences of NArabizi and fined-tuned on a small treebank of this language leads to performance close to those obtained with the same architecture pre- trained on large multilingual and monolingual models. Confirming these results a on much larger data set of noisy French user-generated content, we argue that such character-based language models can be an asset for NLP in low-resource and high language variability set- tings.

pdf
Synthetic Data Augmentation for Zero-Shot Cross-Lingual Question Answering
Arij Riabi | Thomas Scialom | Rachel Keraron | Benoît Sagot | Djamé Seddah | Jacopo Staiano
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing

Coupled with the availability of large scale datasets, deep learning architectures have enabled rapid progress on the Question Answering task. However, most of those datasets are in English, and the performances of state-of-the-art multilingual models are significantly lower when evaluated on non-English data. Due to high data collection costs, it is not realistic to obtain annotated data for each language one desires to support. We propose a method to improve the Cross-lingual Question Answering performance without requiring additional annotated data, leveraging Question Generation models to produce synthetic samples in a cross-lingual fashion. We show that the proposed method allows to significantly outperform the baselines trained on English data only. We report a new state-of-the-art on four datasets: MLQA, XQuAD, SQuAD-it and PIAF (fr).