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Internet Searching: The Hidden Internet

This guide will enable you to understand what is available on the Internet, how to use search engines, and how to find information on the "hidden Internet." You will also learn how to evaluate Internet resources.

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The Hidden Internet

The "Hidden Internet," sometimes called the "Deep Web" or the "Invisible Web," has been estimated to be 500 times larger than the indexable Web (Michael K. Bergman, "The Deep Web: Surfacing Hidden Value").


Why are so many Web pages hidden?
  • Intranets and other protected areas with password restrictions.
  • Subscription databases requiring passwords.
  • Database technology that precludes page-level indexing.
  • Sites that generate "on-the-fly" Web pages in response to user input.
  • Non-textual repositories (satellite imagery, sound files, video files).
Some examples of Hidden Internet sites

Reference Librarian

Christopher C. Brown's picture
Christopher C. Brown
University Libraries

University of Denver

(303) 871-3404