AGAI at SemEval-2026 Task 10: Enhancing Conspiracy Detection via Instruction-tuned LLMs

Xiandong Ran


Abstract
This paper presents our solution for subtask2, which focuses on the automated detection of conspiracy in text. Unlike traditional toxic text detection, conspiracy identification is particularly challenging as it often lacks explicit semantic indicators. To address this, we leveraged a Large Language Model (LLM) as our backbone and employed Low-Rank Adaptation (LoRA) for fine-tuning to enhance detection performance. To generate probabilistic confidence scores while maintaining the generative capabilities of the LLM, we implemented a hybrid loss function that integrates both generative and token classification losses. Additionally, semi-supervised learning with unlabeled data was incorporated to further refine classification accuracy. Our approach achieved a test accuracy of 0.87, ranking 2nd in both stages of the competition leaderboard.
Anthology ID:
2026.semeval-1.259
Volume:
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2065–2069
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.259/
DOI:
Bibkey:
Cite (ACL):
Xiandong Ran. 2026. AGAI at SemEval-2026 Task 10: Enhancing Conspiracy Detection via Instruction-tuned LLMs. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 2065–2069, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
AGAI at SemEval-2026 Task 10: Enhancing Conspiracy Detection via Instruction-tuned LLMs (Ran, SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.259.pdf