VARH-AI at SemEval-2026 Task 10: Exploiting Architectural Diversity with Transformer-SSM Ensembles and Confidence-Based Iterative Refinement for Conspiracy Detection
Hritav Solanki, Shubham Sharma, Manish Prasad, Rakhi Agrawal, Yashvardhan Sharma
Abstract
This paper describes our system for SemEval 2026 Task 10 (PsyCoMark), focusing on Subtask 2: binary conspiracy classification in Reddit submission statements. We present a heterogeneous ensemble approach that combines Transformer-based models (DeBERTa, RoBERTa) with State-Space Models (Mamba) to leverage architectural diversity for improved generalization. Our key contributions include: (1) Bidirectional Mamba (BiMamba), adapting state-space sequence models for bidirectional document classification; (2) (2) a safety-switched multi-task training setup that uses marker supervision only for gold-annotated samples, preventing noisy pseudo-labeled rows from affecting the span extraction objective; and (3) Confidence-Based Iterative Refinement, using committee voting for high-quality pseudo-label generation. Our best official submission achieved a weighted F1 score of 0.78 on the Subtask 2 test set, ranking 4th on the public CodaBench leaderboard. We provide detailed ablation studies demonstrating the complementary contributions of each architectural component to inform future research directions.- Anthology ID:
- 2026.semeval-1.138
- 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:
- 1000–1005
- Language:
- URL:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.138/
- DOI:
- Cite (ACL):
- Hritav Solanki, Shubham Sharma, Manish Prasad, Rakhi Agrawal, and Yashvardhan Sharma. 2026. VARH-AI at SemEval-2026 Task 10: Exploiting Architectural Diversity with Transformer-SSM Ensembles and Confidence-Based Iterative Refinement for Conspiracy Detection. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 1000–1005, San Diego, California, USA. Association for Computational Linguistics.
- Cite (Informal):
- VARH-AI at SemEval-2026 Task 10: Exploiting Architectural Diversity with Transformer-SSM Ensembles and Confidence-Based Iterative Refinement for Conspiracy Detection (Solanki et al., SemEval 2026)
- PDF:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.138.pdf