Walter Dempsey is an Assistant Professor of Biostatistics and Assistant Research Professor at the Institute for Social Research. His research focuses on statistical methods for digital and mobile health. His current work involves three complementary research themes: (1) experimental design and data analytic methods to inform multi-stage decision making in health; (2) statistical modeling of complex longitudinal and survival data; and (3) statistical modeling of complex relational structures such as interaction networks. In the coming years, he will continue to design and apply novel statistical methodologies to make sense of complex longitudinal, survival, and relational datasets. This work will inform decision making in health by aiding in intervention evaluation and development. Prior to joining, he was a postdoctoral fellow in the Department of Statistics at Harvard University where he worked within the Statistical Reinforcement Learning Lab under the supervision of Susan Murphy. He received his PhD in Statistics at the University of Chicago under the supervision of Peter McCullagh.