Hofstadter's law is a self-referential adage, coined by Douglas Hofstadter in his book Gödel, Escher, Bach: An Eternal Golden Braid (1979) to describe the widely experienced difficulty of accurately estimating the time it will take to complete tasks of substantial complexity:
Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.
In 1979, Hofstadter introduced the law in connection with a discussion of chess-playing computers, which at the time were continually being beaten by top-level human players, despite outpacing humans in depth of analysis. Hofstadter wrote:
In the early days of computer chess, people used to estimate that it would be ten years until a computer (or program) was world champion. But after ten years had passed, it seemed that the day a computer would become world champion was still more than ten years away... This is just one more piece of evidence for the rather recursive Hofstadter's Law.
- Law of Accelerating Returns – Perceived increase in the rate of technological change throughout history
- Lindy effect – Paradoxical decrease in mortality rate with age
- List of eponymous laws – Adages and sayings named after a person
- Ninety–ninety rule – Humorous aphorism in computer programming
- Optimism bias – Type of cognitive bias
- Parkinson's law – Adage that work expands to fill its available time
- Planning fallacy – Cognitive bias of underestimating time needed
- Reference class forecasting – Method of predicting the future
- Student syndrome – Planned procrastination
- Valve Time – American video game company
- Vierordt's law – law of time perception relating perceived duration to actual duration
- Waters, Donald J.; Commission on Preservation and Access (1992). Electronic technologies and preservation. Commission on Preservation and Access. ISBN 9781887334167. Retrieved 2011-06-08.
- Gödel, Escher, Bach: An Eternal Golden Braid. 20th anniversary ed., 1999, p. 152. ISBN 0-465-02656-7.
- David M. Goldschmidt (October 3, 1983). "The trials and tribulations of a cottage industrialist". InfoWorld. InfoWorld Media Group, Inc. 5 (40): 16. Retrieved 2011-06-08.
- Gödel, Escher, Bach: An Eternal Golden Braid, Basic Books 1979, Vintage Books Edition, 1980, p. 152.
- Gödel, Escher, Bach: An Eternal Golden Braid. 20th anniversary ed., 1999, p. 152. ISBN 0-465-02656-7
- Rawson, Hugh (2002). Unwritten Laws: The Unofficial Rules of Life as Handed Down by Murphy and Other Sages. Book Sales. p. 115. ISBN 9780785815433. Retrieved 2011-06-08.
- "Hofstadter's Law". The Unwritten Laws of Life. 2008. Archived from the original on 2011-08-26.