Grace Y. Yi is the Statistical Society of Canada 2025 Gold Medal recipient. Grace is professor and Tier I Canada Research Chair in Data Science at the University of Western Ontario. She joined Western in July 2019 after nearly two decades at the University of Waterloo, where she began as a postdoctoral fellow in January 2000 and held positions as assistant, associate and full professor, and finally, university research chair.
Born in Sichuan province, China, Grace obtained her bachelor’s and Master’s degrees in mathematics from Sichuan University. She then taught advanced mathematics at the University of Electronic Science and Technology in China before moving to Canada in 1995 to pursue graduate studies in statistics. She obtained her MSc in statistics from York University in 1996 and her PhD in statistics from the University of Toronto in 2000, under the supervision of Don Fraser. Her thesis, “On the Structure of Asymptotic Distributions,” laid the foundation for her deep engagement with theoretical statistics. During her PhD studies, she also worked with Nancy Reid as a research assistant for the book The Theory of the Design of Experiments.
Although her initial encounters with statistics were marked by dislike or even aversion, her doctoral studies completely transformed her perspective. With the inspiring mentorship of Don Fraser and Nancy Reid, she moved from struggling with concepts such as confidence intervals to becoming immersed in statistical research. Her time at the University of Toronto led her into what she now calls “the wonderland of statistical science.”
Grace began her postdoctoral fellowship at the University of Waterloo and subsequently joined the faculty there. Collaborating with eminent scholars including Richard Cook, Jack Kalbfleisch, Mary Thompson, and Jerry Lawless, she focused on developing new methods for missing data, data measured with error, survival data, and longitudinal data. This productive period marked the beginning of her longstanding commitment to methodological development in statistics and biostatistics.
Her contributions to the field are both foundational and far-reaching. Internationally recognized as a leading expert in measurement error and missing data, Grace was among the first to address the intertwined complexities of these issues by introducing a unified framework. These aspects of noisy data—individually challenging and even more so in combination—present serious barriers to valid inference and model development. Grace’s pioneering work in this space has influenced a broad range of applied and theoretical research. She is the author of the monograph Statistical Analysis with Measurement Error or Misclassification: Strategy, Method, and Application (2017) and coeditor of the Handbook of Measurement Error Models (with Aurore Delaigle and Paul Gustafson, 2021). Grace has also made substantial contributions to foundational statistical inference methods, including composite likelihood theory, estimating functions, likelihood-based inference, causal inference, and high-dimensional data analysis. She is coauthor of the monograph Likelihood and its Extensions (with Nancy Reid and Cristiano Varin, 2025).
Since joining Western, Grace has expanded her research into machine learning, with a focus on statistical methods that address modern data challenges related to label noise, missing data, source-free domain adaptation, transfer learning, boosting, and deep learning. Her work at the intersection of statistical science and machine learning has led to robust methodologies for analyzing noisy and incomplete data, bringing new insights and perspectives.
A passionate educator and mentor, Grace has mentored many postdoctoral fellows and MSc students and has supervised 23 PhD students. In 2023 her efforts were recognized with the Award for Excellence in Graduate Student Mentoring by Western.
Grace is a fellow of the IMS and the American Statistical Association, and an elected member of the International Statistical Institute. She received the CRM–SSC Prize in 2010. Her paper with Xianming Tan and Runze Li was awarded the Canadian Journal of Statistics Award in 2016. In 2025 she delivered the Myra Samuels Memorial Lecture at Purdue University. She served as co-editor in chief of the Electronic Journal of Statistics (2022–24), editor in chief of the Canadian Journal of Statistics (2016–18), and is currently editor of the methodology section of the New England Journal of Statistics in Data Science. She has served as president of the SSC (2021–22) and of its Biostatistics Section (2016), and as chair of the ASA Lifetime Data Science Section (2023). In 2012 she founded the Canada chapter of the International Chinese Statistical Association.
Grace credits much of her success to her collaborators and students. She is especially grateful to her family, who have been a continuous source of inspiration and strength.
The citation for the award reads: “In recognition of an impactful and extensive body of research on statistical theory and methodology, with a special focus on missing and mismeasured data and applications in biostatistics; and for her leadership in statistical science in Canada.”
[Slightly condensed from the Liaison article at https://ssc.ca/en/publications/ssc-liaison/vol-39-3-2025-06/grace-y-yi-ssc-gold-medalist-2025]