Team Duo at SemEval-2026 Task 13: Fine-tuning CodeBERT for Out-of-Distribution AI-Generated Code Detection
Subhiksha G, Sanjai M, Rajalakshmi Sivanaiah, Angel Deborah S
Abstract
This paper addresses detecting AI-generated code in out-of-distribution settings by fine-tuning CodeBERT on algorithmic code from C++, Python, and Java. While the model achieves near-perfect performance on training data (F1 = 0.9935), it degrades significantly on unseen languages and domains (F1 = 0.3532). The high recall (0.8789) but low precision (0.2210) indicates over-prediction of machine-generated code. Error analysis reveals three failure modes: domain mismatch, unfamiliar syntax patterns, and insufficient training. Multi-epoch training and domain-specific augmentation are needed to improve OOD generalization.- Anthology ID:
- 2026.semeval-1.265
- 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:
- 2104–2107
- Language:
- URL:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.265/
- DOI:
- Cite (ACL):
- Subhiksha G, Sanjai M, Rajalakshmi Sivanaiah, and Angel Deborah S. 2026. Team Duo at SemEval-2026 Task 13: Fine-tuning CodeBERT for Out-of-Distribution AI-Generated Code Detection. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 2104–2107, San Diego, California, USA. Association for Computational Linguistics.
- Cite (Informal):
- Team Duo at SemEval-2026 Task 13: Fine-tuning CodeBERT for Out-of-Distribution AI-Generated Code Detection (G et al., SemEval 2026)
- PDF:
- https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.265.pdf