Grace Hopper and the Origin of “Debugging”

By Phineas Upham

Any IT technician who debugs some code can thank Grace Brewster Murray Hopper for coining the term. She was a high-level computer programmer for the Navy throughout the World War II era of American military history, and she was one of the earliest advocates of machine learning.

Grace began her interest in computers at an early age. She had a deep curiosity about the inner workings of an alarm clock. Before her mother realized why all the alarm clocks in the house were “broken”, Grace had dismantled seven to figure out how they worked inside.

She attended Vassar, after some difficulty in the application process, but took a hiatus to join the United States Naval Reserve. Weighing in at 105 pounds, Hopper needed an exemption because she was below the Navy’s minimum weight standard. She trained at the Naval Reserve Midshipman’s School, and graduated in 1944. She served in the Mark I Computer programming division, which functioned something like an analytical engine for predictions. It was to be used to assist the Allied war effort towards the end of World War II.

Hopper was one of the first people who wrote a compiler for a computer. By 1952, the compiler was operational, and her colleagues were astounded. Prior to that moment, PCs were used as little more than glorified calculators.

Hopper also popularized the idea that computer programming should be written in a language that was easy to understand, rather than a machine language. Her ideas helped create the foundation for COBOL, which was one of the earliest high-level programming languages in computing history.

If you’re curious about the “de-bug” term, it involved a literal de-bugging. Hopper pulled a living moth from a computer at one point, as it had been interfering with the delicate circuitry inside.


About the Author: Phineas Upham is an investor at a family office/ hedgefund, where he focuses on special situation illiquid investing. Before this position, Phin Upham was working at Morgan Stanley in the Media and Telecom group. You may contact Phin on his Phineas Upham website or Twitter page.