People

Dr. Johnny Zhang is a Professor of Quantitative Psychology at the University of Notre Dame. He is the director of the Lab for Big Data Methodology at Notre Dame. His research aims to develop better statistical methods and software in the areas of education, health, management, and psychology. He has conducted research in Bayesian methods, Big data analysis, Structural equation modeling, Longitudinal data analysis, Mediation analysis, and Statistical computing and programming. His most recent research involves the development of new methods for social network and text analysis. Dr. Zhang is a fellow of the American Psychological Association and an elected member of the Society of Multivariate Experimental Psychology. Dr. Zhang is the Editor of the Journal of Behavioral Data Science.

Ziqian is a 5th year Ph.D. student in Quantitative Psychology at the University of Notre Dame. Her research interests include Bayesian statistics, statistical computing, and social network analysis. She is passionate about developing statistical methods and software to analyze complex data structures. Ziqian has experience in programming with R, Python, and Stan.

Austin Wyman is a graduate student in quantitative psychology at the University of Notre Dame. His research interests include psychometrics, machine learning, and clinical psychology.

Zongyu Li a PhD student in quantitative psychology with a strong methodological focus on measuring, modeling, and predicting real-life dynamic psychological and social processes, investigating how these processes fluctuate in real-time and evolve over the life spans. His work follows two main avenues: the development of cutting-age statistical models, including longitudinal/time-series analysis, multilevel modeling, network analysis and causal inference; and the advancement of machine learning and AI methods for big data and data integration, involving text, behavioral, physiological, and spatial data. He is also especially interested in applying these methods within the fields of mental health, social and environmental psychology.

Huimin Ding is a Doctor Candidate of Education and PhD Student at Renmin University of China in Beijing, whose research is concentrated on adolescent mental health and behavior in the digital age, particularly exploring issues like internet addiction and cyberbullying among young people. Her work, which falls under the disciplines of Developmental Psychology, Media Psychology, and Social Psychology, focuses on understanding the underlying causes and mechanisms driving these behaviors. She has published multiple articles in journals such as the Journal of Interpersonal Violence and Current Psychology on topics including the link between cyberbullying victimization and perpetration, the role of need for uniqueness in problematic internet use, and the vicious cycle between loneliness and problematic smartphone use.

Xinkai Du is a doctoral candidate in Psychometrics and Quantitative Psychology at the University of Oslo (UiO), focusing on advanced Statistical Modeling in Psychology and Psychiatry using multivariate statistics, networks, SEM, and deep learning. His primary research involves the Norwegian MAP-19 and COVIDMENT projects, applying these sophisticated statistical methods to large-scale data to study mental morbidity trajectories during the COVID-19 pandemic. With a Research Master from the University of Amsterdam and a Bsc from the University of Waterloo, his experience includes recent and ongoing roles as a Visiting Researcher at Stanford University (Oct 2025 - Present) and a Research Collaborator at the National University of Singapore on network modeling.