Ever since man started recording information, it has been important to find ways of retrieving it. Information that cannot be located or decoded cannot benefit anyone.
Librarians were the original guardians of information. Documents that were deposited in a library were categorized by subject or by author to make them more easily retrieved. However, as document collections grew, it became very difficult to manage the information. Sometimes the documents were placed in the wrong section and they got lost for some time. There was always the perennial problem of book theft or failure by a borrower to return the books.
One way of managing books in the libraries was through a card catalog. Several cards were created for each book. One set of cards would be organized by author name and another card would be sorted by book title. More cards could be created, depending how the information was to be searched. In 1876, Melvil Dewey published a system for organizing the documents of a library which became known as the Dewey Decimal Classification (DDC), or Dewey Decimal System. This system assigned hierarchical numerical values to a subject matter and its subdivisions.
|Numbers||Dewey Decimal System Categories|
|000-099||General References or Works (encyclopedias, biographies, periodicals and journalism)|
|100-199||Philosophy, psychology and logic|
|200-299||Religion (men’s faith)|
|300-399||Social Sciences (how people live and work in society; law, government and institutions)|
|400-499||Language (English, grammar and dictionaries)|
|500-599||Natural Science (Mathematics, astronomy, physics, chemistry, geology, paleontology, biology, zoology, and botany)|
|600-699||Technology and Applied Science (medicine, engineering, agriculture, home economics, radio, TV, and aviation)|
|700-799||Fine Arts and Recreation (architecture, sculpture, painting, music, photography and recreation)|
|800-899||Literature (plays, poems, essays, literature in foreign languages)|
|900-999||History and Biography (history, biography, geography and other related disciplines)|
The advent of computers revolutionized the way in which documents are stored and retrieved. While it may still be necessary to have a filing system for physical copies of documents, documents in computer-readable form can be stored in a database. Every word of an electronic document can be indexed, unlike the manual system that used index cards. It is now possible to search not only authors and titles, but any word combination. A semantic search seeks to improve search accuracy by understanding searcher intent and by using the contextual meaning of terms as they appear in the searchable dataspace.
The keywords in the left column list topics of common interest. Click on the links to read more about each topic. Each page explains the concept and allows searching for topics of relevance.