蔣兆凱 / Chao-Kai Chiang

Machine learning for imperfect supervision and adaptive decision making.

I develop principled machine learning methods for imperfect supervision, noisy labels, online learning, and bandit feedback.

My work connects theory, algorithms, and practical systems for learning when labels are weak or unreliable, distributions shift, or feedback is partial and sequential.

Portrait of Chao-Kai Chiang
Chao-Kai Chiang Assistant Professor Department of Computer Science National Yang Ming Chiao Tung University

Recruiting

Prospective students

I welcome motivated students interested in principled machine learning, especially weak supervision, noisy labels, distribution shift, online learning, bandit algorithms, and adaptive learning systems. Prospective students are encouraged to email me with a CV and a brief description of their research interests.

Research Vision

Learning reliably from imperfect supervision and adaptive feedback.

Modern machine learning is increasingly deployed in settings where clean labels, stable distributions, and complete feedback are unavailable. My research aims to build a principled foundation for learning under such realistic conditions: weak or noisy supervision, distribution shift, sequential feedback, and adaptive decision making. The long-term goal is to understand the weakest yet learnable forms of supervision and to design algorithms that remain reliable beyond idealized data assumptions.

3,647+ Google Scholar citations
2,979 citations for Federated Multi-Task Learning
327 citations for Online Optimization with Gradual Variations

Research

Research agenda

My current research develops theory and algorithms for machine learning systems that must learn from imperfect supervision, changing environments, and partial feedback. I focus on problems where statistical reliability, optimization behavior, and practical applicability must be studied together.

Weak and noisy supervision

I study weakly supervised learning and learning with label noise, including unified risk analysis, reliable validation under noisy labels, robust imitation learning from vague feedback, and learning under complex supervision transitions.

Online learning and bandits

I develop algorithms and regret analyses for online convex optimization and multi-armed bandits, with interests in best-of-both-worlds guarantees, Thompson sampling, Pareto front identification, and contextual or dueling feedback.

Adaptive learning systems

I connect theoretical insights with practical systems, including federated multi-task learning, budgeted hyper-parameter tuning, LLM routing, and adaptive decision making with preference or bandit feedback.

17 WSL/LLN settings unified in recent risk-analysis work
NeurIPS, ICML, COLT Publications spanning both theory and applied machine learning
2012 Mark Fulk Best Student Paper Award at COLT
Weakly supervised learning Learning with label noise Multi-armed bandits Online convex optimization Robust machine learning Foundation model feedback

Selected Publications

Representative papers

Selected first by recent top-conference publications, then by citation impact within the main research areas.

NeurIPS 2023Weak supervision / imitation learning13 citations

Imitation Learning from Vague Feedback

Xin-Qiang Cai, Yu-Jie Zhang, Chao-Kai Chiang, and Masashi Sugiyama

Applies weakly supervised learning ideas to recover useful imitation signals from vague feedback.

NeurIPS 2017Federated learning2,979 citations

Federated Multi-Task Learning

Virginia Smith, Chao-Kai Chiang, Maziar Sanjabi, and Ameet Talwalkar

A systems-aware federated multi-task learning framework for heterogeneous distributed data.

COLT 2012Online learning327 citationsBest Student Paper

Online Optimization with Gradual Variations

Chao-Kai Chiang, Tianbao Yang, Chia-Jung Lee, Mehrdad Mahdavi, Chi-Jen Lu, Rong Jin, and Shenghuo Zhu

Introduced variation-aware regret analysis for online optimization in gradually changing environments.

Publications

Full publication list

The list below is compiled from the uploaded publication list and CV. Use the filters to browse by category.

Publication PDF Google Scholar DBLP
2023ConferenceNeurIPS

Imitation Learning from Vague Feedback

Xin-Qiang Cai, Yu-Jie Zhang, Chao-Kai Chiang, and Masashi Sugiyama

Advances in Neural Information Processing Systems, pp. 48275-48292.

2017ConferenceNeurIPS

Federated Multi-Task Learning

Virginia Smith, Chao-Kai Chiang, Maziar Sanjabi, and Ameet Talwalkar

Advances in Neural Information Processing Systems, pp. 4424-4434.

2012ConferenceCOLT

Online Optimization with Gradual Variations

Chao-Kai Chiang, Tianbao Yang, Chia-Jung Lee, Mehrdad Mahdavi, Chi-Jen Lu, Rong Jin, and Shenghuo Zhu

Annual Conference on Learning Theory, pp. 6.1-6.20. Mark Fulk Best Student Paper Award.

2010ConferenceSODA

Online Learning with Queries

Chao-Kai Chiang and Chi-Jen Lu

Annual ACM-SIAM Symposium on Discrete Algorithms, pp. 616-629.

2025PreprintarXiv

LLM Routing with Dueling Feedback

Chao-Kai Chiang, Takashi Ishida, and Masashi Sugiyama

arXiv:2510.00841. Under double-blind review in uploaded publication list.

Contact

Get in touch

Department of Computer Science
National Yang Ming Chiao Tung University