bbStar at SemEval-2025 Task 10: Improving Narrative Classification and Explanation via Fine Tuned Language Models

Rishit Tyagi, Rahul Bouri, Mohit Gupta


Abstract
Understanding covert narratives and implicit messaging is essential for analyzing bias and sentiment. Traditional NLP methods struggle with detecting subtle phrasing and hidden agendas. This study tackles two key challenges: (1) multi-label classification of narratives and sub-narratives in news articles, and (2) generating concise, evidence-based explanations for dominant narratives. We fine-tune a BERT model with a recall-oriented approach for comprehensive narrative detection, refining predictions using a GPT-4o pipeline for consistency. For narrative explanation, we propose a ReACT (Reasoning + Acting) framework with semantic retrieval-based few-shot prompting, ensuring grounded and relevant justifications. To enhance factual accuracy and reduce hallucinations, we incorporate a structured taxonomy table as an auxiliary knowledge base. Our results show that integrating auxiliary knowledge in prompts improves classification accuracy and justification reliability, with applications in media analysis, education, and intelligence gathering.
Anthology ID:
2025.semeval-1.290
Volume:
Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025)
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Sara Rosenthal, Aiala Rosá, Debanjan Ghosh, Marcos Zampieri
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2233–2239
Language:
URL:
https://preview.aclanthology.org/transition-to-people-yaml/2025.semeval-1.290/
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Bibkey:
Cite (ACL):
Rishit Tyagi, Rahul Bouri, and Mohit Gupta. 2025. bbStar at SemEval-2025 Task 10: Improving Narrative Classification and Explanation via Fine Tuned Language Models. In Proceedings of the 19th International Workshop on Semantic Evaluation (SemEval-2025), pages 2233–2239, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
bbStar at SemEval-2025 Task 10: Improving Narrative Classification and Explanation via Fine Tuned Language Models (Tyagi et al., SemEval 2025)
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https://preview.aclanthology.org/transition-to-people-yaml/2025.semeval-1.290.pdf