Calvin Mooers

American computer scientist

Calvin Northrup Mooers (October 4, 1919December 1, 1994) was an American computer scientist known for his work in information retrieval and for the programming language TRAC.


  • The requirements of information retrieval, of finding information whose location or very existence is a priori unknown.
    • Calvin Mooers (1947); cited in. Eugene Garfield (1997) "A Tribute To Calvin N. Mooers, A Pioneer Of Information Retrieval." The Scientist, Vol:11, #6, p. 9, March 17, 1997
  • The problem of directing a user to stored information, some of which may be unknown to him, is the problem of "information retrieval"… In information retrieval, the addressee or receiver rather than the sender is the active party. Other differences are that communication is temporal from one epoch to a later epoch in time, though possibly at the same point in space; communication is in all cases unidirectional; the sender cannot know the particular message that will be of later use to the receiver and must send all possible messages; the message is digitally representable; a "channel" is the physical document left in storage which contains the message; and there is no channel noise because all messages are presumed to be completely accessible to the receiver. The technical goal is finding in minimum time those messages of interest to the receiver, where the receiver has available a selective device with a finite digital scanning rate.
  • Information retrieval is the name for the process or method whereby a prospective user of information is able to convert his need for information into an actual list of citations to documents in storage containing information useful to him. It is the finding or discovery process with respect to stored information. It is another, more general, name for the production of a demand bibliography. Information retrieval embraces the intellectual aspects of the description of information and its specification for search, and also whatever systems, technique, or machines that are employed to carry out the operation. Information retrieval is crucial to documentation and organization of knowledge.
    • Calvin Mooers (1951) "Zatocoding applied to mechanical organization of knowledge." American Documentation, 2, p. 25; Cited in: Birger Hjørland (2006) "Information retrival (IR)" on
  • An information retrieval system will tend not to be used whenever it is more painful and troublesome for a customer to have information than for him not to have it... Where an information retrieval system tends not to be used, a more capable information retrieval system may tend to be used even less.
    • Calvin Mooers (1959) Mooers' law: or, why some retrieval systems are used and others are not. p. 138
  • People will resist information unless the price of not knowing it greatly exceeds the price of learning it.
    • Attributed to Mooers (1959) in Eugene Garfield (1997) "A Tribute To Calvin N. Mooers, A Pioneer Of Information Retrieval." The Scientist, Vol:11, #6, p. 9, March 17, 1997

Quotes about Calvin Mooers

  • In the 1940s Mortimer Taube, Calvin Mooers, and James Perry were the leaders among Americans who began to investigate subject analysis, the coding of subject terms, and their relationship to information retrieval. At the frontiers in a paradigm-breaking era, their approach combined a pragmatic view and abstract thinking.
    • Irene Sekely Farkas-Conn (1990) From documentation to information science: : the beginnings and early development of the American Documentation Institute-American Society for Information Science. p. 136 (online)
  • He was a participant in early developmental work on digital computers, a researcher, author, and implementer of applications in information retrieval; and a prophet in the 1950s describing the future importance of what is now called computer networks and distributive processing, and daring to predict that machines could simulate thought processes in retrieving computerized information. In 1947, he proposed the Zator, an electronic, film-scanning retrieval machine, and made the first proposal to use the Boolean operations or, and, and not to prescribe selections in retrieval machines. He developed his own Zatocoding System in 1948 using superimposed subject codes on edge-notched cards. He coined the term "Information Retrieval" in 1950, and went on from there to obtain several patents in information retrieval and signaling, produce a text-handling language (TRAC), author some 200 publications, and form one of the first companies whose only concern was information. His thinking has affected all who are in the field of Information and his early ideas are now incorporated into today's reality.
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