Computational Story Lab at BLP-2025 Task 1: HateSense: A Multi-Task Learning Framework for Comprehensive Hate Speech Identification using LLMs

Tabia Tanzin Prama, Christopher M. Danforth, Peter Dodds


Abstract
This paper describes HateSense, our multi-task learning framework for the BLP 2025 shared task 1 on Bangla hate speech identification. The task requires not only detecting hate speech but also classifying its type, target, and severity. HateSense integrates binary and multi-label classifiers using both encoder- and decoder-based large language models (LLMs). We experimented with pre-trained encoder models (Bert based models), and decoder models like GPT-4.0, LLaMA 3.1 8B, and Gemma-2 9B. To address challenges such as class imbalance and the linguistic complexity of Bangla, we employed techniques like focal loss and odds ratio preference optimization (ORPO). Experimental results demonstrated that the pre-trained encoders (BanglaBert) achieved state-of-the-art performance. Among different prompting strategies, chain-of-thought (CoT) combined with few-shot prompting proved most effective. Following the HateSense framework, our system attained competitive micro-F1 scores: 0.741 (Task 1A), 0.724 (Task 1B), and 0.7233 (Task 1C). These findings affirm the effectiveness of transformer-based architectures for Bangla hate speech detection and suggest promising avenues for multi-task learning in low-resource languages.
Anthology ID:
2025.banglalp-1.37
Volume:
Proceedings of the Second Workshop on Bangla Language Processing (BLP-2025)
Month:
December
Year:
2025
Address:
Mumbai, India
Editors:
Firoj Alam, Sudipta Kar, Shammur Absar Chowdhury, Naeemul Hassan, Enamul Hoque Prince, Mohiuddin Tasnim, Md Rashad Al Hasan Rony, Md Tahmid Rahman Rahman
Venues:
BanglaLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
430–442
Language:
URL:
https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.banglalp-1.37/
DOI:
Bibkey:
Cite (ACL):
Tabia Tanzin Prama, Christopher M. Danforth, and Peter Dodds. 2025. Computational Story Lab at BLP-2025 Task 1: HateSense: A Multi-Task Learning Framework for Comprehensive Hate Speech Identification using LLMs. In Proceedings of the Second Workshop on Bangla Language Processing (BLP-2025), pages 430–442, Mumbai, India. Association for Computational Linguistics.
Cite (Informal):
Computational Story Lab at BLP-2025 Task 1: HateSense: A Multi-Task Learning Framework for Comprehensive Hate Speech Identification using LLMs (Prama et al., BanglaLP 2025)
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https://preview.aclanthology.org/ingest-ijcnlp-aacl/2025.banglalp-1.37.pdf