About

I work on the mathematics of fairness in automated systems, and on the policy that decides whether any of it matters. Those two halves have not always sat comfortably together, and most of what I do now lives in the space between them.

I direct the Center for Tech Responsibility at Brown, where the work is deliberately practical: pairing students with civil society organizations that need technical review, and building the methods that make that review possible when the system in question is not open to inspection.

Before returning to Brown I served in the White House Office of Science and Technology Policy as Assistant Director for Science and Justice, where I helped write the Blueprint for an AI Bill of Rights. That year taught me more about the limits of technical argument than the previous decade had.

My earlier research was in computational geometry, on structure and approximation in high-dimensional data. It is less separate from the current work than it sounds. The questions that make fairness hard to define are frequently questions about distance, and about what a measurement is willing to ignore.