Detecting Hate Speech in Cross-Lingual and Multi-lingual Settings Using Language Agnostic Representations

The automatic detection of hate speech is a blooming field in the natural language processing community. In recent years there have been efforts in detecting hate speech in multiple languages, using models trained on multiple languages at the same time. Furthermore, there is special interest in the capabilities of language agnostic features to represent text in hate speech detection. This is because models can be trained in multiple languages, and then the capabilities of the model and representation can be tested on a unseen language. In this work we focused on detecting hate speech in mono-lingual, multi-lingual and cross-lingual settings. For this we used a pre-trained language model called Language Agnostic BERT Sentence Embeddings (LabSE), both for feature extraction and as an end to end classification model. We tested different models such as Support Vector Machines and Tree-based models, and representations in particular bag of words, bag of characters, and sentence embeddings extracted from Multi-lingual BERT. The dataset used was the SemEval 2019 task 5 data set, which covers hate speech against immigrants and women in English and Spanish. The results show that the usage of LabSE as feature extraction improves the performance on both languages in a mono-lingual setting, and in a cross-lingual setting. Moreover, LabSE as an end to end classification model performs better than the reported by the authors of SemEval 2019 task 5 data set for the Spanish language.