NUST PsyAI at SemEval-2026 Task 10: Parameter-Efficient RoBERTa for Conspiracy Detection and Character-Level Marker Extraction

Mian Muhammad Husnain Akram, Mehwish Fatima


Abstract
We present the NUST PsyAI system for SemEval-2026 Task 10 (PsyCoMark), targeting document-level conspiracy detection and character-level psycholinguistic marker extraction from Reddit discourse. Our system ranks 7th in Extraction and 8th in Detection on the leaderboard. We benchmark feature-based and transformer approaches, adopting RoBERTalarge with LoRA for parameter-efficient finetuning. For detection, RB-DET-LoRA outperforms all baselines, achieving weighted F1 0.79 (dev) and 0.76 (test), with robust generalization under blinded evaluation. For extraction, we contrast a unified multi-type BIO scheme with a decomposed per-type setup; the latter mitigates cross-label interference and improves boundary consistency, reaching Overlap F1 of 0.16 (dev) and 0.21 (test). Results reveal a clear asymmetry: detection benefits from contextual semantic modeling, while extraction is limited by sparse supervision and boundary-sensitive evaluation.
Anthology ID:
2026.semeval-1.170
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
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Pages:
1298–1307
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URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.170/
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Bibkey:
Cite (ACL):
Mian Muhammad Husnain Akram and Mehwish Fatima. 2026. NUST PsyAI at SemEval-2026 Task 10: Parameter-Efficient RoBERTa for Conspiracy Detection and Character-Level Marker Extraction. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 1298–1307, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
NUST PsyAI at SemEval-2026 Task 10: Parameter-Efficient RoBERTa for Conspiracy Detection and Character-Level Marker Extraction (Akram & Fatima, SemEval 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.170.pdf
Supplementarymaterial:
 2026.semeval-1.170.SupplementaryMaterial.zip