Hao Cheng
Hao Cheng is a Principal Researcher at Microsoft Research and Affiliate Faculty at the University of Washington whose work spans biomedical language models, open-domain question answering, tool-using agents and human-LLM collaboration. After earning an MSc at the University of Alberta, he completed a PhD at the University of Washington, where he joined the Sounding Board team that won Amazon's inaugural Alexa Prize in 2017 and taught a graduate course on conversational AI in Spring 2019. His 2020 biomedical pretraining paper with Yu Gu, Robert Tinn and Hoifung Poon introduced the BLURB benchmark, and in 2021 it received a Best Paper Award in ACM Transactions on Computing for Healthcare while he published UnitedQA as first author. He coauthored Chameleon, Chain-of-Skills and LLaVA-Plus in 2023, along with the GRIN mixture-of-experts training method and Generative Adapter in 2024. In 2025, his paper CollabLLM on training language models for multiturn collaboration received an Outstanding Paper Award at ICML 2025.
- Now at
- Microsoft Research and University of Washington
Timeline
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2017
Winning the Alexa Prize
He earns an MSc at the University of Alberta under Dale Schuurmans and Csaba Szepesvári and a PhD at the University of Washington with Mari Ostendorf. In 2017, as a University of Washington electrical engineering doctoral student working with team leader Hao Fang and Allen School doctoral students Elizabeth Clark, Ari Holtzman and Maarten Sap, he is on the Sounding Board team that wins Amazon's inaugural Alexa Prize and its $500,000 first prize.
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2019
Teaching conversational AI at Washington
At the University of Washington in Spring 2019, he serves as instructor for the graduate course E596/LING 580 on conversational AI.
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2020
Biomedical language model pretraining
In 2020, he coauthors a paper with Yu Gu, Robert Tinn and Hoifung Poon showing that pretraining language models from scratch on biomedical text gives substantial gains over continual pretraining of general-domain models. The work releases pretrained models and introduces the BLURB benchmark with a public leaderboard.
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2021
UnitedQA and a healthcare paper award
He is first author of UnitedQA in 2021, written with Yelong Shen, Xiaodong Liu, Pengcheng He, Weizhu Chen and Jianfeng Gao, which combines an extractive and a generative reader to beat earlier models by 3.3 exact-match points on NaturalQuestions and 2.7 on TriviaQA. In 2021, his biomedical pretraining paper with Yu Gu, Robert Tinn, Hoifung Poon and colleagues receives a Best Paper Award in ACM Transactions on Computing for Healthcare.
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2023
Chameleon, Chain-of-Skills and LLaVA-Plus
In April 2023, he coauthors Chameleon, a NeurIPS 2023 LLM system that composes tools such as vision models, web search engines and Python functions and reaches 86.54% accuracy on ScienceQA with GPT-4. In 2023, he also coauthors the configurable open-domain question-answering retriever Chain-of-Skills and, in November 2023, the multimodal assistant LLaVA-Plus, which keeps a skill repository of vision and vision-language models to activate tools for user requests.
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2024
GRIN mixture-of-experts training
With 16 coauthors in September 2024, he introduces GRIN (GRadient-INformed MoE), a training method that uses sparse gradient estimation for expert routing so a model with 6.6B activated parameters matches a 14B dense model trained on the same data. In November 2024, he coauthors Generative Adapter with Tong Chen, Hao Fang, Patrick Xia, Xiaodong Liu, Benjamin Van Durme, Luke Zettlemoyer and Jianfeng Gao to contextualize language models in parameters with a single forward pass.
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2025
CollabLLM and an ICML award
CollabLLM, which he coauthors in 2025 with Shirley Wu, Michel Galley, Baolin Peng, James Zou, Jure Leskovec, Jianfeng Gao and others, trains language models for multiturn collaboration using Multiturn-aware Rewards estimated from simulated conversations. In July 2025, the paper receives an Outstanding Paper Award at ICML 2025.
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As of October 2026
Principal researcher at Microsoft
He is a Principal Researcher at Microsoft Research and Affiliate Faculty at the University of Washington.
Career
- NowMicrosoft ResearchPrincipal Researcher
- NowUniversity of WashingtonAffiliate Faculty
Education
Sources and credits
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- Hao Cheng's Homepage
- UW students win Amazon's inaugural Alexa Prize for most engaging socialbot | UW News
- UW Team wins international Amazon Alexa Prize for the design of conversational AI
- Domain-Specific Language Model Pretraining for Biomedical Natural Language Processing
- UnitedQA: A Hybrid Approach for Open Domain Question Answering
- Chameleon: Plug-and-Play Compositional Reasoning with Large Language Models
- Chain-of-Skills: A Configurable Model for Open-domain Question Answering
- LLaVA-Plus: Learning to Use Tools for Creating Multimodal Agents
- GRIN: GRadient-INformed MoE
- Generative Adapter: Contextualizing Language Models in Parameters with A Single Forward Pass
- CollabLLM: From Passive Responders to Active Collaborators
- Congratulations to the #ICML2025 award winners! - AIhub
- Hao Cheng at Microsoft Research



