Research

Diagnosing Model Performance Under Distribution Shift

Tiffany Cai, Steve Yadlowsky, Hongseok Namkoong

Paper link, GitHub link

Under revision at Operations Research; presented at FORC 2023, INFORMS 2023

Summary When a model performs poorly out of distribution, how do we understand why performance became worse? We attribute change in model performance across distributions to X shifts and Y\|X shifts.

Posterior Sampling via Autoregressive Generation

Kelly Wang Zhang*, Tiffany Cai*, Hongseok Namkoong, Daniel Russo

Forthcoming

To be presented at ICLR 2024 Workshop: Generative Models for Decision Making

Summary We recast the problem of principled decision-making under uncertainty (Thompson Sampling) as autoregressive sequential modeling, trained via loss minimization.

Constrained Learning for Causal Inference and Semiparametric Statistics

Tiffany Cai*, Yuri Fonseca*, Kaiwen Hou, Hongseok Namkoong

Forthcoming

Presented at CODE@MIT 2023

Summary We recast the problem of creating asymptotically efficient estimators for the average treatment effect as constrained optimization.

Tutorial: Modeling and Exploiting Data Heterogeneity under Distribution Shifts

Jiashuo Liu, Tiffany Cai, Peng Cui, Hongseok Namkoong

Tutorial link

Presented at NeurIPS 2023