• Multilingual offensive language identification for low-resource languages

      Ranasinghe, Tharindu; Zampieri, Marcos (Association for Computing Machinery, 2021-11-10)
      Offensive content is pervasive in social media and a reason for concern to companies and government organizations. Several studies have been recently published investigating methods to detect the various forms of such content (e.g., hate speech, cyberbullying, and cyberaggression). The clear majority of these studies deal with English partially because most annotated datasets available contain English data. In this article, we take advantage of available English datasets by applying cross-lingual contextual word embeddings and transfer learning to make predictions in low-resource languages. We project predictions on comparable data in Arabic, Bengali, Danish, Greek, Hindi, Spanish, and Turkish. We report results of 0.8415 F1 macro for Bengali in TRAC-2 shared task [23], 0.8532 F1 macro for Danish and 0.8701 F1 macro for Greek in OffensEval 2020 [58], 0.8568 F1 macro for Hindi in HASOC 2019 shared task [27], and 0.7513 F1 macro for Spanish in in SemEval-2019 Task 5 (HatEval) [7], showing that our approach compares favorably to the best systems submitted to recent shared tasks on these three languages. Additionally, we report competitive performance on Arabic and Turkish using the training and development sets of OffensEval 2020 shared task. The results for all languages confirm the robustness of cross-lingual contextual embeddings and transfer learning for this task.
    • Overview of the HASOC subtrack at FIRE 2021: Hate speech and offensive content identification in English and Indo-Aryan languages and conversational hate speech

      Mandl, Thomas; Modha, Sandip; Shahi, Gautam Kishore; Madhu, Hiren; Satapara, Shrey; Majumder, Prasenjit; Schäfer, Johannes; Ranasinghe, Tharindu; Zampieri, Marcos; Nandini, Durgesh; et al. (Association for Computing Machinery, 2021-12-13)
      The HASOC track is dedicated to the evaluation of technology for finding Offensive Language and Hate Speech. HASOC is creating a multilingual data corpus mainly for English and under-resourced languages(Hindi and Marathi). This paper presents one HASOC subtrack with two tasks. In 2021, we organized the classification task for English, Hindi, and Marathi. The first task consists of two classification tasks; Subtask 1A consists of a binary and fine-grained classification into offensive and non-offensive tweets. Subtask 1B asks to classify the tweets into Hate, Profane and offensive. Task 2 consists of identifying tweets given additional context in the form of the preceding conversion. During the shared task, 65 teams have submitted 652 runs. This overview paper briefly presents the task descriptions, the data and the results obtained from the participant's submission.
    • Urdu AI: writeprints for Urdu authorship identification

      Sarwar, Raheem; Hassan, Saeed-Ul (Association for Computing Machinery, 2021-10-31)
      The authorship identification task aims at identifying the original author of an anonymous text sample from a set of candidate authors. It has several application domains such as digital text forensics and information retrieval. These application domains are not limited to a specific language. However, most of the authorship identification studies are focused on English and limited attention has been paid to Urdu. On the other hand, existing Urdu authorship identification solutions drop accuracy as the number of training samples per candidate author reduces, and when the number of candidate author increases. Consequently, these solutions are inapplicable to real-world cases. To overcome these limitations, we formulate a stylometric feature space. Based on this feature space we use an authorship identification solution that transforms each text sample into point set, retrieves candidate text samples, and relies the nearest neighbour classifier to predict the original author of the anonymous text sample. To evaluate our method, we create a significantly larger corpus than existing studies and conduct several experimental studies which show that our solution can overcome the limitations of existing studies and report an accuracy level of 94.03%, which is higher than all previous authorship identification works.