Donald works on the sociology and social history of science and technology, especially those fields that have a major impact on people's lives: the eugenics movement and its effect on science; the development of nuclear weapons; safety-critical and security-critical computer systems. He is currently working on the sociology of the financial markets, and his DIRC research concentrates on financial risk. His most recent books are Knowing Machines (MIT Press, 1996), The Social Shaping of Technology, edited with Judy Wajcman (Open University Press, second edition, 1999), and Mechanizing Proof: Computing, Risk, and Trust (MIT Press, 2001).