CoLearn: An Agentic Tutor that Learns its Learner in a Human–AI Co-Learning Loop

Kailai He, Zhihao Wu, Linhai Zhang, Runcong Zhao, Yulan He, Jiazheng Li


Abstract
Good tutoring adapts to the individual: it tracks what a learner knows, notices why they go wrong, and asks the next question that will help most. Most deployed tutoring tools instead serve fixed item banks and treat a wrong answer as a single bit of signal. We present CoLearn, an interactive, agentic tutor that supports an iterative tutoring loop: the learner practises, and the system builds an evidence-grounded memory of the learner’s mastery and misconceptions. This memory is updated as evidence accumulates and is used to generate the next personalised question. CoLearn has three components: (i) a persistent learner-state memory that updates per-topic mastery with a soft-evidence variant of Bayesian Knowledge Tracing, where a large language model acts as a continuous ob- servation function; (ii) adaptive question generation that targets the learner’s weakest topic and recurring misconceptions; and (iii) an evi- dence view that makes personalisation visible and testable through live progress visualisation and blind A/B comparison. In blind A/B evaluation, questions conditioned on this memory are preferred over non-personalised ones 68–69% of the time, and in persona simulations with hidden ground-truth mastery the agent’s belief converges toward the learner’s true mastery.
Anthology ID:
2026.emnlp-demos.6
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: System Demonstrations
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Sweta Agrawal, Alberto Abad
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
56–65
Language:
URL:
https://aclanthology.org/2026.emnlp-demos.6/
DOI:
Bibkey:
Cite (ACL):
Kailai He, Zhihao Wu, Linhai Zhang, Runcong Zhao, Yulan He, and Jiazheng Li. 2026. CoLearn: An Agentic Tutor that Learns its Learner in a Human–AI Co-Learning Loop. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: System Demonstrations, pages 56–65, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CoLearn: An Agentic Tutor that Learns its Learner in a Human–AI Co-Learning Loop (He et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-demos.6.pdf