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Search engines

Search engines. Christian Rennerskog , Jonas Rosling, Mattias Olsson. What is a search engine?. A search engine is designed to search for information on the World Wide Web. Information may consist of web pages, images, information and other types of files.

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Search engines

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  1. Search engines Christian Rennerskog, Jonas Rosling, Mattias Olsson

  2. What is a search engine? • A search engine is designed to search for information on the World Wide Web. • Information may consist of web pages, images, information and other types of files. • Search engines operate algorithmically or are a mixture of algorithmic and human input.

  3. History – The early days • Before there were search engines there was a complete list of all webservers. • The very first tool used for searching on the (pre-web) Internet was Archie. • Very Easy Rodent-Oriented Net-wide Index to Computerized Archives • Jonzy's Universal Gopher Hierarchy Excavation And Display

  4. History – Web search • The first Web search engine was Wandex. • One of the first "full text" crawler-based search engines was WebCrawler which came out in 1994. • It let users search for any word in any webpage, which became the standard for all major search engines since.

  5. History – The rise of Google • Around 2000, the Google search engine rose to prominence. • Better results with an innovation called PageRank. • This algorithm ranks web pages based on the number and PageRank of other web sites and pages that link there. • As of late 2007, Google was by far the most popular Web search engine worldwide.

  6. Timeline • 1993: Aliweb • 1994: WebCrawler, Infoseek, Lycos • 1995: AltaVista, Open Text, Magellan • 1996:Dogpile • 1997: Northern Light, Yandex • 1998: Google • 1999: AlltheWeb, Naver • 2003: Info.com • 2004: Yahoo! Search, A9.com • 2005: MSN Search, Ask.com, GoodSearch • 2006: Live Search, ChaCha, Guruji.com • 2007:wikiseek, WikiaSearch • 2008: Powerset, Viewzi, Cuil, Boogami

  7. How Web search engines work • A search engine operates, in the following order: Web crawling, Indexing, Searching • Web search engines work by storing information about many web pages. • These pages are retrieved by a Web crawler — an automated Web browser which follows every link it sees. • The contents of each page are then analyzed to determine how it should be indexed.

  8. How Web search engines work • Data about web pages are stored in an index database for use in later queries. • Some search engines store all or part of the source page (referred to as a cache) as well as information about the web pages. • Others store every word of every page they find.

  9. How Web search engines work • When a user enters a query into a search engine (typically by using key words), the engine examines its index and provides a listing of best-matching web pages according to its criteria. • The usefulness of a search engine depends on the relevance of the result set it gives back.

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