When and What to Teach: Budget-Aware Online Adaptation for Web Agents

Jianwei Zhang, Sihan Cao, Pengcheng Zheng, Ya Wen, Pei Ke, Kuien Liu, Shen Gao, Wei Dong, Yang Yang, Chaoning Zhang


Abstract
Web agents have achieved significant success in automating complex internet tasks but deploying them in real-world environments requires continuous online adaptation. Given that deploying powerful proprietary models remains commercially cost-prohibitive, practitioners must rely on lightweight local models that evolve post-deployment via online teaching from a stronger teacher. However, standard interactive feedback imposes prohibitive costs. We show that conventional trajectory-level preference optimization wastes budget on both unresolvable episodes and redundant execution turns. To resolve these inefficiencies, we propose Score-Guided Online Teaching with Budgeted Trajectory Trimming, a budget-aware framework that systematically orchestrates when and what to teach. Specifically, our framework integrates a solvability-aware teacher gate to dictate when to query the teacher model and a score-guided turn selection mechanism to decide what informative turns to retain. Extensive experiments on MiniWoB and TimeWarp demonstrate that our method achieves comparable first-pass success while reducing teacher calls by 22.6% and student training compute by 52.1% on average. Our code is available at https://github.com/zjw131f1fc/budgeted-online-teaching.
Anthology ID:
2026.findings-emnlp.1096
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
23190–23205
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1096/
DOI:
Bibkey:
Cite (ACL):
Jianwei Zhang, Sihan Cao, Pengcheng Zheng, Ya Wen, Pei Ke, Kuien Liu, Shen Gao, Wei Dong, Yang Yang, and Chaoning Zhang. 2026. When and What to Teach: Budget-Aware Online Adaptation for Web Agents. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 23190–23205, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When and What to Teach: Budget-Aware Online Adaptation for Web Agents (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1096.pdf