Key Word in Context

Key Word In Context (KWIC) is the most common format for concordance lines. The term KWIC was coined by Hans Peter Luhn.[1] The system was based on a concept called keyword in titles, which was first proposed for Manchester libraries in 1864 by Andrea Crestadoro.[2]

A KWIC index is formed by sorting and aligning the words within an article title to allow each word (except the stop words) in titles to be searchable alphabetically in the index.[3] It was a useful indexing method for technical manuals before computerized full text search became common.

For example, a search query including all of the words in an example definition ("KWIC is an acronym for Key Word In Context, the most common format for concordance lines") and the Wikipedia slogan in English ("the free encyclopedia"), searched against a Wikipedia page, might yield a KWIC index as follows. A KWIC index usually uses a wide layout to allow the display of maximum 'in context' information (not shown in the following example).

KWIC is an acronym for Key Word In Context, ... page 1
... Key Word In Context, the most common format for concordance lines. page 1
... the most common format for concordance lines. page 1
... is an acronym for Key Word In Context, the most common format ... page 1
Wikipedia, The Free Encyclopedia page 0
... In Context, the most common format for concordance lines. page 1
Wikipedia, The Free Encyclopedia page 0
KWIC is an acronym for Key Word In Context, the most ... page 1
  KWIC is an acronym for Key Word ... page 1
... common format for concordance lines. page 1
... for Key Word In Context, the most common format for concordance ... page 1
  Wikipedia, The Free Encyclopedia page 0
KWIC is an acronym for Key Word In Context, the most common ... page 1

A KWIC index is a special case of a permuted index.[4] This term refers to the fact that it indexes all cyclic permutations of the headings. Books composed of many short sections with their own descriptive headings, most notably collections of manual pages, often ended with a permuted index section, allowing the reader to easily find a section by any word from its heading. This practice, also known as Key Word Out of Context (KWOC), is no longer common.

  • Keyword alongside context (KWAC)
    Keyword alongside context (KWAC)
  • Keyword in context (KWIC)
    Keyword in context (KWIC)
  • Keyword out of context (KWOC)
    Keyword out of context (KWOC)
  1. ^ Manning, C. D.; Schütze, H. (1999). Foundations of Statistical Natural Language Processing. The MIT Press. p. 35.
  2. ^ "Advanced Indexing and Abstracting Practices". Atlantic Publishers & Distributors. 1989. p. 41. Retrieved 26 March 2019 – via Google Books.
  3. ^ "KWIC indexes and concordances". Archived from the original on 2016-06-06. Retrieved 2016-06-17.
  4. ^ "3. Theory of KWIC indexing". Infohost.nmt.edu. Archived from the original on 14 May 2019. Retrieved 26 March 2019.