TeamXBC at BEA 2026 Shared Task 1: How AI (and I) won the shared task: Vibe and agentic coding solutions for practical machine learning problems

Xiaobin Chen


Abstract
The paper describes how the author used AI coding agents and a technique called vibe coding to successfully tackle the BEA 2026 shared task on vocabulary difficulty prediction. Three sets of predictions (runs) were submitted to the competition, corresponding to three experiments the author ran by giving the coding agent different levels of agency: (1) a one-off solution fully planned and implemented by the AI, (2) an AI self-determined iterative process that ran for 24 hours, and (3) a collaborative human-in-the-loop process where solutions were discussed between the author and the AI. Competition results showed that the collaborative mode delivered the best performance, demonstrating that at the current stage domain expert input and decision making are important and necessary for vibe coding solutions to practical machine learning problems.
Anthology ID:
2026.bea-1.68
Volume:
Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Bashar Alhafni, Stefano Bannò, Marie Bexte, Jill Burstein, Andrea Horbach, Ronja Laarmann-Quante, Anais Tack, Victoria Yaneva, Zheng Yuan
Venues:
BEA | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
997–1009
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bea-1.68/
DOI:
Bibkey:
Cite (ACL):
Xiaobin Chen. 2026. TeamXBC at BEA 2026 Shared Task 1: How AI (and I) won the shared task: Vibe and agentic coding solutions for practical machine learning problems. In Proceedings of the 21st Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2026), pages 997–1009, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
TeamXBC at BEA 2026 Shared Task 1: How AI (and I) won the shared task: Vibe and agentic coding solutions for practical machine learning problems (Chen, BEA 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.bea-1.68.pdf