CIC at SemEval-2019 Task 5: Simple Yet Very Efficient Approach to Hate Speech Detection, Aggressive Behavior Detection, and Target Classification in Twitter (original) (raw)

CiTIUS-COLE at SemEval-2019 Task 5: Combining Linguistic Features to Identify Hate Speech Against Immigrants and Women on Multilingual Tweets

This article describes the strategy submitted by the CiTIUS-COLE team to SemEval 2019 Task 5, a task which consists of binary classification where the system predicts whether a tweet in English or in Spanish is hateful against women or immigrants or not. The proposed strategy relies on combining linguistic features to improve the classifier's performance. More precisely, the method combines textual and lexical features, embedding words with the bag of words in Term Frequency-Inverse Document Frequency (TF-IDF) representation. The system performance reaches about 81% F1 when it is applied to the training dataset, but its F1 drops to 36% on the official test dataset for the English and 64% for the Spanish language concerning the hate speech class.

SemEval-2019 Task 5: Multilingual Detection of Hate Speech Against Immigrants and Women in Twitter

Proceedings of the 13th International Workshop on Semantic Evaluation

The paper describes the organization of the SemEval 2019 Task 5 about the detection of hate speech against immigrants and women in Spanish and English messages extracted from Twitter. The task is organized in two related classification subtasks: a main binary subtask for detecting the presence of hate speech, and a finer-grained one devoted to identifying further features in hateful contents such as the aggressive attitude and the target harassed, to distinguish if the incitement is against an individual rather than a group. HatEval has been one of the most popular tasks in SemEval-2019 with a total of 108 submitted runs for Subtask A and 70 runs for Subtask B, from a total of 74 different teams. Data provided for the task are described by showing how they have been collected and annotated. Moreover, the paper provides an analysis and discussion about the participant systems and the results they achieved in both subtasks.

LT3 at SemEval-2019 Task 5: Multilingual Detection of Hate Speech Against Immigrants and Women in Twitter (hatEval)

Proceedings of the 13th International Workshop on Semantic Evaluation, 2019

This paper describes our contribution to the SemEval-2019 Task 5 on the detection of hate speech against immigrants and women in Twitter (hatEval). We considered a supervised classification-based approach to detect hate speech in English tweets, which combines a variety of standard lexical and syntactic features with specific features for capturing offensive language. Our experimental results show good classification performance on the training data, but a considerable drop in recall on the held-out test set.

IIIT-Hyderabad at HASOC 2019: Hate Speech Detection

2019

Copyright c ©2019 for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). FIRE 2019, 12-15 December 2019, Kolkata, India. Abstract. Automatic identification of offensive language in various social media platforms especially Twitter poses a great challenge to the AI community. The repercussions of such writings are hazardous to individuals, communities, organizations and nations. The HASOC shared task attempts for automatic detection of abusive language on Twitter in English, German and Hindi languages. As a part of this task, we (team A3-108) submitted different machine learning and neural network based models for all the languages. Our best performing model was an ensemble model of SVM, Random Forest and Adaboost classifiers with majority voting.

Machine learning techniques for hate speech classification of twitter data: State-of-the-art, future challenges and research directions

Computer Science Review, 2020

Twitter is a microblogging tool that allow the creation of big data through short digital contents. This study provides a survey of machine learning techniques for hate speech classification from Twitter data streams. Hate speech classification in Twitter data streams has remain a vibrant research focus, but little research efforts have been devoted to the design of a generic metadata architecture, threshold settings and fragmentation issues. Hate speech classification techniques presented in literature address some of the challenges inherent in Twitter data streams but limited in the aforementioned issues. This study presented collection of hate speech benchmarks datasets suitable for testing the efficiency of classification models. This study also presented the pros and cons for single and hybrid machine learning methods in hate speech classification. The summary of performance evaluation for the surveyed machine learning methods was also presented. The study also presented a generic metadata architecture for hate speech classification in Twitter to tackle issues with Twitter data streams. The developed generic metadata architecture was observed to performed better across all evaluation metrics for hate speech detection having 0.95, 0.93, 0.92 and 0.93 for accuracy, precision, recall and F1-score respectively, when compared to similar methods. Similarly, the developed generic metadata architecture for hate speech sentiment classification performed better with F1-score of 91.5% compared to related methods. The developed generic metadata architecture also indicates a more perfect test having an AUC of 0.97, when compared to similar methods. The statistical validation of results points out the efficiency of the developed system. Finally, the results also showed that the developed system is very good for automatic topic detection and categorization.

Cita en Amores, J. et al. Detecting ideological hatred on Twitter. Development and evaluation of a political ideology hate speech detector in tweets in Spanish. Cuadernos.info, (49), 98-124.

https://doi.org/10.7764/cdi.49.27817, 2021

AbstrAct | Hate speech spread through social media such as Twitter deserves special attention, as its increase may be related to the rise in hate crimes. Of the 11 categories of discrimination contemplated by the Spanish Ministry of Internal Affairs, the second in which the most hate crimes are registered per year is political ideology. However, this category falls outside of most action plans to study and combat hate crimes. The same occurs in the case of academic works since most focus on analyzing and detecting hate in English and at a general level. The few authors who have targeted their studies to a single type of hate to improve accuracy, have focused on racism, xenophobia, or gender discrimination, but never on political ideology. Furthermore, the detection prototypes developed so far have not used databases generated manually by various coders. This paper aims to overcome these limitations, developing and evaluating an automatic hate speech detector on Twitter in Spanish for reasons of ideological discrimination, using supervised machine learning techniques. For this, we developed a total of eight predictive models from an ad-hoc generated training corpus, and making use of shallow modelling, but also deep learning, which has allowed to improve the final performance of the prototype. In addition, the development of the corpus allowed us to observe that 16.2% of the sample, collected in autumn 2019 and manually analyzed, included some type of ideological hatred. Keywords: hate speech; online hate; Twitter; political ideology; deep learning; machine learning; supervised classification.

A Multilingual Evaluation for Online Hate Speech Detection

ACM Transactions on Internet Technology, 2020

The increasing popularity of social media platforms such as Twitter and Facebook has led to a rise in the presence of hate and aggressive speech on these platforms. Despite the number of approaches recently proposed in the Natural Language Processing research area for detecting these forms of abusive language, the issue of identifying hate speech at scale is still an unsolved problem. In this article, we propose a robust neural architecture that is shown to perform in a satisfactory way across different languages; namely, English, Italian, and German. We address an extensive analysis of the obtained experimental results over the three languages to gain a better understanding of the contribution of the different components employed in the system, both from the architecture point of view (i.e., Long Short Term Memory, Gated Recurrent Unit, and bidirectional Long Short Term Memory) and from the feature selection point of view (i.e., ngrams, social network–specific features, emotion lex...

UA at SemEval-2019 Task 5: Setting A Strong Linear Baseline for Hate Speech Detection

Proceedings of the 13th International Workshop on Semantic Evaluation, 2019

This paper describes the system developed at the University of Alicante (UA) for the Se-mEval 2019 Task 5: Multilingual detection of hate speech against immigrants and women in Twitter. The purpose of this work is to build a strong baseline for hate speech detection by means of a traditional machine learning approach with standard textual features, which could serve as a reference to compare with deep learning systems. We participated in both task A (Hate Speech Detection against Immigrants and Women) and task B (Aggressive behavior and Target Classification) for both English and Spanish. Given the text of a tweet, task A consists of detecting hate speech against women or immigrants in the text, whereas task B consists of identifying the target harassed as individual or generic, and to classify hateful tweets as aggressive or not aggressive. Despite its simplicity, our system obtained a remarkable macro-F1 score of 72.5 (sixth highest) and an accuracy of 73.6 (second highest) in Spanish (task A), outperforming more complex neural models from a total of 40 participant systems.

KBCNMUJAL@HASOC-Dravidian-CodeMix-FIRE2020: Using Machine Learning for Detection of Hate Speech and Offensive Codemix Social Media text

2020

This paper describes the system submitted by our team, KBCNMUJAL, for Task 2 of the shared task Hate Speech and Offensive Content Identification in Indo-European Languages (HASOC), at Forum for Information Retrieval Evaluation, December 16-20, 2020, Hyderabad, India. The datasets of two Dravidian languages Viz. Malayalam and Tamil of size 4000 observations, each were shared by the HASOC organizers. These datasets are used to train the machine using different machine learning algorithms, based on classification and regression models. The datasets consist of tweets or YouTube comments with two class labels offensive and not offensive. The machine is trained to classify such social media messages in these two categories. Appropriate n-gram feature sets are extracted to learn the specific characteristics of the Hate Speech text messages. These feature models are based on TFIDF weights of n-gram. The referred work and respective experiments show that the features such as word, character ...

Afaan Oromo Hate Speech Detection and Classification on Social Media

European Language Resources Association (ELRA), 2022

Hate and offensive speech on social media is targeted to attack an individual or group of community based on protected characteristics such as gender, ethnicity, and religion. Hate and offensive speech on social media is a global problem that suffers the community especially, for an under-resourced language like Afaan Oromo language. One of the most widely spoken Cushitic language families is Afaan Oromo. Our objective is to develop and test a model used to detect and classify Afaan Oromo hate speech on social media. We developed numerous models that were used to detect and classify Afaan Oromo hate speech on social media by using different machine learning algorithms (classical, ensemble, and deep learning) with the combination of different feature extraction techniques such as BOW, TF-IDF, word2vec, and Keras Embedding layers. To perform the task, we required Afaan Oromo datasets, but the datasets were unavailable. By concentrating on four thematic areas of hate speech, such as gender, religion, race, and offensive speech, we were able to collect a total of 12,812 posts and comments from Facebook. BiLSTM with pre-trained word2vec feature extraction is an outperformed algorithm that achieves better accuracy of 0.84 and 0.88 for eight classes and two classes, respectively.