Ziyang Guo
PhD student in Computer Science at Northwestern University
Hello! I’m Ziyang Guo. I’m a fourth-year PhD student in Computer Science at Northwestern University. Currently, I work with Professor Jessica Hullman at MU Colective. Previously, I received my B.S. in Computer Science from Zhejiang University in China.
I study how to design AI systems that are complementary partners in decision-making. My work integrates human–computer interaction, statistical decision theory, and machine learning. I use statistical decision theory to formalize and measure complementarity in human–AI pipelines, build explainability techniques that communicate human-complementary evidence in model outputs, and develop post-training approaches for LLMs that optimize for downstream human–AI decision quality rather than standalone model accuracy.