Knuth reward check

In the preface of each of his books and on his website, [See [http://sunburn.stanford.edu/~knuth/books.html Books in Print by Donald E. Knuth] ] computer scientist Donald Knuth offers to cheerfully pay a reward of $2.56 (USD) to the first finder of each error in one of his published books (also for the sneak previews of Volume 4), whether it be technical, typographical, or historical. Knuth explains that $2.56, or 256 cents, corresponds to one hexadecimal dollar. [ [http://sunburn.stanford.edu/~knuth/faq.html Frequently Asked Questions] on [http://sunburn.stanford.edu/~knuth/ Don Knuth's webpage] ] Valuable suggestions are worth 32¢.

These reward checks have been described as "among computerdom's most prized trophies". [Steve Ditlea. [http://www.technologyreview.com/articles/99/09/ditlea0999.asp Rewriting the Bible in 0's and 1's] . "MIT's "Technology Review", 11 January 2002.] As of October 2001, Knuth reports having written more than 2,000 such checks, with an average value exceeding $8 per check. [http://www.ams.org/notices/200203/fea-knuth.pdf AMS] ] As of March 2005, the total value of the checks signed by Knuth was over $20,000 (see NPR interview below). Very few of these checks are actually cashed, however, even the largest ones; more often, they are framed, or kept as "bragging rights".Kara Platoni, [http://www.stanfordalumni.org/news/magazine/2006/mayjun/features/knuth.html Love at First Byte] . Stanford Magazine, May-June 2006] [The [http://www.tug.org/whatis.html History of TeX] ]

: "Intelligence: Finding an error in a Knuth text.": "Stupidity: Cashing that $2.56 check you got.": Seen in a Slashdot signature, quoted by Edward O'Connor [ [http://stgray.com/index.php?option=com_content&task=category&sectionid=4&id=36&Itemid=26 Quotes About Programming] ]

The reward for coding errors found in Knuth's TeX and METAFONT programs (as distinguished from errors in Knuth's books) followed an audacious scheme inspired by the Wheat and Chessboard Problem. [MathWorld|title=Wheat and Chessboard Problem|urlname=WheatandChessboardProblem] It started at $2.56, and doubled every year until it reached $327.68. Recipients of this "sweepstakes" reward include Chris Thompson (Cambridge) and Boguslaw Jackowski (Gdansk), [ [http://www.uni-giessen.de/hrz/tex/more_info/info/mailarchiv/mutex.1995/msg00147.html Installation of Knuth's 1995 release ] ] and also Peter Breitenlohner on 20 March 1995. [ [http://www.tug.org/TUGboat/Articles/tb17-1/tb50knut.pdf TUG'95: Questions and Answers with Prof. Donald E. Knuth] and Ch 34 of Digital Typography]

Knuth is often not able to answer immediately when a reader finds a mistake in one of his books or programs; in some cases, the delay has been several years long. For example, on 1 July 1996, Knuth sent out more than 250 letters, 125 of which contained checks, for errors reported in "The Art of Computer Programming" since the summer of 1981. A few of these remain unclaimed as of May 2006. [ [http://www-cs-staff.Stanford.EDU/~knuth/address.html What is your current mailing address?] on Don Knuth's website.] When Knuth is not able to reply immediately, he adds 5% interest, compounded continuously, to the reward. [See [http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimPDF/king.pdf King Solomon and Rabbi Ben Ezra’s Evaluations of Pi] , and [http://developers.slashdot.org/comments.pl?sid=29586&pid=3178058#3178872 Slashdot] .]

Each check's memo field identifies the book and page number. 1.23 indicates an error on page 23 of Volume 1. (1.23) indicates a valuable suggestion on that page. The symbol Θ denotes the book "Things a Computer Scientist Rarely Talks About", KLR denotes the book "Mathematical Writing" (by Knuth, Larrabee, and Roberts), GKP and CM denote the book "Concrete Mathematics" (by Graham, Knuth, and Patashnik), f1 denotes fascicle 1, CMT denotes the book "Computer Modern Typefaces", DT denotes the book "Digital Typography", and SN denotes "Surreal Numbers".

Notes and references

External links

* [http://www.npr.org/templates/story/story.php?storyId=4532247 Interview] (RealVideo format) (or [http://www.soundbytes.org/phpBB2/viewtopic.php?t=5643&sid=bf7d0d454451865c6409201cf55746f5 Transcript] ) with Knuth on National Public Radio