Our research encompasses diverse projects and collaborations at the University of Washington and beyond. Find below information about the PI and about students at the University of Washington that are part of our team.


Johannes Lederer

Johannes is a Tenure-Track Assistant Professor of Statistics and an Adjunct Assistant Professor of Biostatistics at the University of Washington. His educational training spans physics, mathematics, and statistics. After receiving a MSc in Physics, he started his Doctor of Sciences under the supervision of Sara van de Geer and Peter Bühlmann at ETH Zürich in December 2009 and completed the degree in December 2012. After that, he was a postdoctoral researcher hosted by Martin Wainwright at UC Berkeley, until he accepted the position as the Jacob Wolfowitz Visiting Assistant Professor in the Department of Statistical Science at Cornell University in August 2013. In September 2015, he then joined the University of Washington.


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Fei He

Fei is a research scientist at the Institute for Health Metrics and Evaluation, University of Washington. She completed her PhD in Biostatistics with minor in epidemiology under the supervision of Jaroslaw Harezlak at the Indiana University in 2016. Her research is focused on methodology development for the analysis of ecological momentary assessment (EMA) diary data regarding sexual transmitted infections (STIs). Her expertise comprises longitudinal data analysis, survival analysis, functional data analysis, and joint modeling of multiple outcomes. Fei is now working on global, regional, and national incidence and mortality for HIV in the Globe Burden of Disease group and is also pursuing her interest in STI related data further.

Néhémy Lim

Néhémy joined Johannes’ group in Department of Statistics at the University of Washington in September 2015 as a postdoctoral Research Associate. He received an Engineer’s degree in Computer Science at ENSIIE (France) in 2011 and a Master’s degree in Systems biology at the Université d’Évry Val-d’Essonne (France) the same year. Then, he completed a PhD program under the supervision of Florence d’Alché-Buc (Institut Mines-Télécom/Télécom ParisTech, France) and Cédric Auliac (CEA, France) from 2012 to 2015. Néhémy’s research interest concerns the development of efficient machine learning methods for learning from large and complex data. For more information, visit his website:


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Yunqi Bu

Yunqi is a third year PhD student in Biostatistics at UW. She received her Bachelor’s degree in Mathematics from Nankai University, China, in 2013. Currently, she is working with Johannes on graphical models for high-dimensional data. In particular, she is developing models and methods to study brain connectivity. Visit her webpage for more information:

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David Gold

David is a second-year Ph.D. student in the Department of Statistics. His research interests include high-dimensional statistics, semi-/non-parameteric inference, statistical computation, and the interplay of statistics and differential geometry. David works with Johannes and Professor Jing Tao to develop estimators for high-dimensional instrumental variables models. He received his B.A. in philosophy and mathematics from Williams College in 2012.

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Lun Li

Lun has recently earned his Bachelor’s degree in Statistics and Economics from University of Washington, and is now pursuing a Master’s degree in Statistics at UW. Lun is currently working with Johannes on the development and application of statistical methodology for microbial networks.

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Wei Li

Wei is a third year PhD student in statistics at Peking University, China. Currently, he is a visiting student at the Biostatistics Department at the University of Washington. He received his Bachelor degree from Nankai University, China. His research is focused on causal inference, missing data, and high-dimensional statistics. Wei is working with Johannes on tuning parameter selection for penalized logistic regression.

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Peiran Liu

Peiran is a STAT PhD student at UW. This will be his second year of his PhD life, and fourth year at UW in Seattle. He has been working as a data scientist intern at CDK Global. In school, he is working with Professor Adrian Raftery in Demographic Statistics and with Johannes in high dimension statistics. Peiran is interested in all kinds of machine learning techniques, both from a theoretical and practical point of view. If anyone wants to discuss with him about something of the above, do not hesitate to contact him. Peiran has also many interests outside work. He likes all kinds of card games, especially bridge, and he plays mahjong and Hearthstone. Additionally, he plays badminton and table tennis. He is looking forward to playing those games with you guys together.

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Lu Yu

Lu is a first year Master’s student in Statistics at the University of Washington. She received her Bachelor degree in Mathematics and Applied Mathematics at the Shandong University, China. Currently, Lu and Johannes work on Oracle Inequalities for high-dimensional prediction.

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Rui Zhuang

Rui is a second year PhD student of Biostatistics at the University of Washington. Before joining the University of Washington, Rui received her Bachelor degree from Nanjing University, China and was a research assistant of genetics at Hong Kong University of Science and Technology. Currently, Rui is working with Johannes on high dimensional statistical inference. They are particularly interested in networks. For more information, please visit her website: .


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Rosemary Adams

Rosemary is in her third year at UW and is pursuing her undergraduate degree in Informatics, with a focus on data science. In addition to research, she is also a teaching assistant for an introductory Informatics course. She is also a member of UW’s Chamber Dance Company.

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Sam Gehman

Sam is a sophomore pursuing a degree in the technology field at the University of Washington. He makes backend solutions for the HDIM Research Group with bash and R programs. He previously worked on setting up the website for HDIM. Currently he is an intern at Motorola Solutions where he creates software for the iOS platform involving Push-to-Talk communications.

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Kimberly Ha

Kimberly is a Senior pursuing a double degree in Human-Centered Design & Engineering and Mathematics. She worked in HDIM, programming the output of plots and facilitating the design process for the logo and branding. Along with Gina Lee, she created this website for Johannes Lederer.

Kimberly is the former President of The Society of Asian Scientists & Engineers at UW and has collaborated with Dr. Scott Miles to advance visual analytics and user interfaces for regional disaster resilience. In addition to working as a public speaking tutor at UW Public Speaking Center, she is also working full-time as a SAP CoE Intern at Weyerhauser until the beginning of 2017.

Gina Lee

Gina is a third year student studying Human Centered Design and Engineering. Currently, she is working on developing Johannes’ website and previously worked on web development and design for the HDIM Group. Within the department of Human Centered Design and Engineering, she has been researching rumoring and the spread of misinformation online during crisis events and has been involved in researching disaster response in the Cascadia Rising exercise. For her extracurriculars, she is the Chair of Mentorship for the Society of Asian Scientists and Engineers and is an officer for the Chamber Music Club at UW.

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Donghui Mai

Donghui is a senior in Statistics and Applied & Computational Math Sciences at the University of Washington. She is now working on a toolbox for reproducible research in high-dimensional statistics. In particular, she is developing algorithms for efficient and realistic data generation in regression and network settings.

Yijia Liu photo

Yijia Liu

Yijia is a recent graduate with BS in Economics and Applied & Computational Math Sciences. Currently, she is developing STI software and improving the efficiency and generality of algorithms used for predictions based on imperfect diagnostic tests. Yijia is a former undergraduate team assistant in the Washington Experimental Mathematics Lab, Optimization in Neural Networks team, and she is a former tutor in MSC and IC. Yijia’s main research interest is Machine Learning in Artificial Intelligence, and she is applying for a PhD position in this area. Also check out Yijia’s github .