Congratulations to Our Newest PhD Graduate, Dr. Anna Flowers!

The Department of Statistics at Virginia Tech is proud to announce and celebrate the successful completion of Dr. Anna Flowers's doctoral degree requirements.

Dr. Anna Flowers successfully defended her dissertation titled "Multi-Stage Modeling with Gaussian Processes" on April 28, 2026, a significant milestone representing years of rigorous work, dedication, and impactful research.

Title: Multi-Stage Modeling with Gaussian Processes

Abstract: Gaussian processes (GPs) furnish accurate nonlinear predictions with well-calibrated uncertainty. However, GPs alone are not always flexible enough to model complex real-world phenomena. To remedy this issue, it is beneficial to chain together multiple models. These so-called multi-stage models fit models in sequence, using output from one model as training data in the next model. I utilize multi-stage modeling with GPs to achieve two tasks. First, I improve GP prediction accuracy for data from processes with sudden changes, or "jumps," in the output variable by creating a new cluster-based (latent) feature and adding it to the input matrix. Then, I fit a GP to understand the circumstances under which a machine learning (ML) model performs best, and use that GP to propose the best circumstances in which to make future data acquisitions.  I do this by treating the composition of metadata and the performance of the ML model, respectively, as the inputs and output of a GP.  I vet both methods on a selection of real and synthetic benchmark examples from the recent literature.

Dr. Anna Flowers will be joining Disney as a Decision Scientist.