Information retrieval

[2] Depending on the application the data objects may be, for example, text documents, images,[3] audio,[4] mind maps[5] or videos.

[6] there is ... a machine called the Univac ... whereby letters and figures are coded as a pattern of magnetic spots on a long steel tape.

By this means the text of a document, preceded by its subject code symbol, can be recorded ... the machine ... automatically selects and types out those references which have been coded in any desired way at a rate of 120 words a minuteThe idea of using computers to search for relevant pieces of information was popularized in the article As We May Think by Vannevar Bush in 1945.

[7] It would appear that Bush was inspired by patents for a 'statistical machine' – filed by Emanuel Goldberg in the 1920s and 1930s – that searched for documents stored on film.

Automated information retrieval systems were introduced in the 1950s: one even featured in the 1957 romantic comedy Desk Set.

In the 1960s, the first large information retrieval research group was formed by Gerard Salton at Cornell.

By the 1970s several different retrieval techniques had been shown to perform well on small text corpora such as the Cranfield collection (several thousand documents).

The introduction of web search engines has boosted the need for very large scale retrieval systems even further.