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 recursive analysis. Conventional wisdom held that the strength of human players lay in their ability to focus on particular positions rather than follow every possible line of play to its ultimate conclusion. 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
- 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
- Vierordt's law
- 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.