 She was especially instrumental in developing the ONR's implementation of projects studying mathematical algorithms for computing, as well as university research programs to build computers such as Project Whirlwind at MIT.She was an early proponent of magnetic-core and electrostatic memory, the use of transistor components rather than vacuum tubes, and the design of machines with visual displays and multiple inputs.The New York Times wrote "Dr. Rees also had an important role in the growth and diversification of mathematical studies.