Web search engine {{redirect|Search engine}} A '''Web search engine''' is a [[search engine (computing)|search engine]] designed to search for information on the [[World Wide Web]]. Information may consist of [[web page]]s, images and other types of files. Some search engines also mine data available in newsbooks, databases, or [[Web directory|open directories]]. Unlike [[Web directories]], which are maintained by human editors, search engines operate algorithmically or are a mixture of [[algorithmic]] and human input. ==History== {|class="bordered infobox" |- ! colspan = "3" | Timeline |- | colspan = "3" | Note: "Launch" refers only to web
availability of original crawl-based
web search engine results. |- !|Year !|Engine !|Event |- ||1993 ||[[Aliweb]] ||Launch |- | rowspan="3" |1994 ||[[WebCrawler]] ||Launch |- ||[[Infoseek]] ||Launch |- ||[[Lycos]] ||Launch |- | rowspan="4" |1995 ||[[AltaVista]] ||Launch (part of [[Digital Equipment Corporation|DEC]]) |- ||[[Magellan]] ||Launch (The McKinley Group) |- ||[[Excite]] ||Launch |- ||[[SAPO]] ||Launch |- | rowspan="4" |1996 ||[[Dogpile]] ||Launch |- ||[[Inktomi]] ||Founded |- ||[[HotBot]] ||Founded |- ||[[Ask Jeeves]] ||Founded |- | rowspan="2" |1997 ||[[Northern Light Group|Northern Light]] ||Launch |- ||[[Yandex|Yandex]] ||Launch |- ||1998 ||[[Google Search|Google]] ||Launch |- |rowspan="4"|1999 ||[[AlltheWeb]] ||Launch |- ||[[Naver]] ||Launch |- ||[[Teoma]] ||Founded |- ||[[Vivisimo]] ||Founded |- |rowspan="1"|2000 ||[[Baidu]] ||Founded |- |rowspan="1"|2003 ||[[Info.com]] ||Launch |- | rowspan="2" |2004 ||[[Yahoo! Search]] ||Final launch |- ||[[A9.com]] ||Launch |- | rowspan="3" |2005 ||[[MSN Search]] ||Final launch |- ||[[Ask.com]] || Launch |- ||[[GoodSearch]] || Launch |- | rowspan= "6" |2006 ||[[wikiseek]] ||Founded |- ||[[Quaero]] ||Founded |- ||[[Ask.com]] || Launch |- || [[Live Search]] ||Launch |- || [[ChaCha (search engine)|ChaCha]] || Beta Launch |- ||[[Guruji.com]] ||Beta Launch |- | rowspan= "1" |2007 ||[[wikiseek]] ||Launched |} Before there were search engines there was a complete list of all webservers. The list was edited by [[Tim Berners-Lee]] and hosted on the CERN webserver. One historical snapshot from 1992 remainshttp://www.w3.org/History/19921103-hypertext/hypertext/DataSources/WWW/Servers.html. As more and more webservers went online the central list could not keep up. On the NCSA Site new servers were announced under the title "What's New!", but no complete listing existed any morehttp://home.mcom.com/home/whatsnew/whats_new_0294.html. The very first tool used for searching on the (pre-web) Internet was [[Archie search engine|Archie]]. "Internet History - Search Engines" (from [[Search Engine Watch]]), Universiteit Leiden, Netherlands, September 2001, web: [http://www.internethistory.leidenuniv.nl/index.php3?c=7 LeidenU-Archie]. The name stands for "archive" without the "v". It was created in 1990 by [[Alan Emtage]], a student at [[McGill University]] in Montreal. The program downloaded the directory listings of all the files located on public anonymous FTP ([[File Transfer Protocol]]) sites, creating a searchable database of file names; however, Archie did not index the contents of these sites. The rise of [[Gopher (protocol)|Gopher]] (created in 1991 by [[Mark McCahill]] at the [[University of Minnesota]]) led to two new search programs, [[Veronica (computer)|Veronica]] and [[Jughead (computer)|Jughead]]. Like Archie, they searched the file names and titles stored in Gopher index systems. Veronica ('''V'''ery '''E'''asy '''R'''odent-'''O'''riented '''N'''et-wide '''I'''ndex to '''C'''omputerized '''A'''rchives) provided a keyword search of most Gopher menu titles in the entire Gopher listings. Jughead ('''J'''onzy's '''U'''niversal '''G'''opher '''H'''ierarchy '''E'''xcavation '''A'''nd '''D'''isplay) was a tool for obtaining menu information from specific Gopher servers. While the name of the search engine "[[Archie search engine|Archie]]" was not a reference to the [[Archie Comics|Archie comic book]] series, "[[Veronica Lodge|Veronica]]" and "[[Jughead Jones|Jughead]]" are characters in the series, thus referencing their predecessor. The first Web search engine was Wandex, a now-defunct index collected by the [[World Wide Web Wanderer]], a [[web crawler]] developed by Matthew Gray at [[Massachusetts Institute of Technology|MIT]] in 1993. Another very early search engine, [[Aliweb]], also appeared in 1993. [[JumpStation]] (released in early 1994) used a crawler to find web pages for searching, but search was limited to the title of web pages only. One of the first "full text" crawler-based search engines was [[WebCrawler]], which came out in 1994. Unlike its predecessors, it let users search for any word in any webpage, which became the standard for all major search engines since. It was also the first one to be widely known by the public. Also in 1994 [[Lycos]] (which started at [[Carnegie Mellon University]]) was launched, and became a major commercial endeavor. Soon after, many search engines appeared and vied for popularity. These included [[Magellan]], [[Excite]], [[Infoseek]], [[Inktomi]], [[Northern Light Group|Northern Light]], and [[AltaVista]]. [[Yahoo!]] was among the most popular ways for people to find web pages of interest, but its search function operated on its [[web directory]], rather than full-text copies of web pages. Information seekers could also browse the directory instead of doing a keyword-based search. In 1996, [[Netscape]] was looking to give a single search engine an exclusive deal to be their featured search engine. There was so much interest that instead a deal was struck with Netscape by 5 of the major search engines, where for $5Million per year each search engine would be in a rotation on the Netscape search engine page. These five engines were: [[Yahoo!]], [[Magellan]], [[Lycos]], [[Infoseek]] and [[Excite]]. Search engines were also known as some of the brightest stars in the Internet investing frenzy that occurred in the late 1990s.{{cite journal |last=Gandal |first=Neil |authorlink= |coauthors= |year=2001 |month= |title=The dynamics of competition in the internet search engine market |journal=International Journal of Industrial Organization |volume=19 |issue=7 |pages=1103–1117 |doi=10.1016/S0167-7187(01)00065-0 |url= |accessdate= |quote= }} Several companies entered the market spectacularly, receiving record gains during their [[initial public offering]]s. Some have taken down their public search engine, and are marketing enterprise-only editions, such as Northern Light. Many search engine companies were caught up in the [[dot-com bubble]], a speculation-driven market boom that peaked in 1999 and ended in 2001. Around 2000, the [[Google Search|Google search engine]] rose to prominence.{{Fact|date=February 2008}} The company achieved better results for many searches with an innovation called [[PageRank]]. This iterative algorithm ranks web pages based on the number and PageRank of other web sites and pages that link there, on the premise that good or desirable pages are linked to more than others. Google also maintained a minimalist interface to its search engine. In contrast, many of its competitors embedded a search engine in a [[web portal]]. By 2000, Yahoo was providing search services based on [[Inktomi]]'s search engine. Yahoo! acquired [[Inktomi]] in 2002, and [[Overture]] (which owned [[AlltheWeb]] and [[AltaVista]]) in 2003. Yahoo! switched to Google's search engine until 2004, when it launched its own search engine based on the combined technologies of its acquisitions. Microsoft first launched MSN Search (since re-branded [[Live Search]]) in the fall of 1998 using search results from [[Inktomi]]. In early 1999 the site began to display listings from [[Looksmart]] blended with results from [[Inktomi]] except for a short time in 1999 when results from [[AltaVista]] were used instead. In 2004, Microsoft began a transition to its own search technology, powered by its own [[web crawler]] (called [[msnbot]]). As of late 2007, Google was by far the most popular Web search engine worldwide.[http://searchengineland.com/070921-105613.php Nielsen NetRatings: August 2007 Search Share Puts Google On Top, Microsoft Holding Gains], ''SearchEngineLand'', September 21, 2007 [http://searchengineland.com/071010-192830.php comScore: August 2007 Google Top Worldwide Search Engine; Baidu Beats Microsoft] A number of country-specific search engine companies have become prominent; for example [[Baidu]] is the most popular search engine in the [[People's Republic of China]] and [[guruji.com]] in [[India]].{{cite web| url=http://moneycentral.msn.com/investor/research/profile.asp?Symbol=BIDU| title=MSN Money - BIDU| publisher=MSN Money| accessdate=2006-05-11}} ==How Web search engines work== {{Unreferencedsection|date=November 2007}} A search engine operates, in the following order # [[Web crawling]] # [[Index (search engine)|Indexing]] # [[Web search query|Searching]] Web search engines work by storing information about many web pages, which they retrieve from the WWW itself. These pages are retrieved by a [[Web crawler]] (sometimes also known as a spider) — an automated Web browser which follows every link it sees. Exclusions can be made by the use of [[robots.txt]]. The contents of each page are then analyzed to determine how it should be [[Search engine indexing|indexed]] (for example, words are extracted from the titles, headings, or special fields called [[meta tags]]). Data about web pages are stored in an index database for use in later queries. Some search engines, such as [[Google]], store all or part of the source page (referred to as a [[web cache|cache]]) as well as information about the web pages, whereas others, such as [[AltaVista]], store every word of every page they find. This cached page always holds the actual search text since it is the one that was actually indexed, so it can be very useful when the content of the current page has been updated and the search terms are no longer in it. This problem might be considered to be a mild form of [[linkrot]], and Google's handling of it increases [[usability]] by satisfying [[user expectations]] that the search terms will be on the returned webpage. This satisfies the [[principle of least astonishment]] since the user normally expects the search terms to be on the returned pages. Increased search relevance makes these cached pages very useful, even beyond the fact that they may contain data that may no longer be available elsewhere. When a user enters a [[web search query|query]] into a search engine (typically by using [[Keyword (Internet search)|key word]]s), the engine examines its [[inverted index|index]] and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text. Most search engines support the use of the [[boolean operators]] AND, OR and NOT to further specify the [[web search query|search query]]. Some search engines provide an advanced feature called [[Proximity search (text)|proximity search]] which allows users to define the distance between keywords. The usefulness of a search engine depends on the [[relevance (information retrieval)|relevance]] of the '''result set''' it gives back. While there may be millions of webpages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to [[rank order|rank]] the results to provide the "best" results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another. The methods also change over time as Internet usage changes and new techniques evolve. Most Web search engines are commercial ventures supported by [[advertising]] revenue and, as a result, some employ the controversial practice of allowing advertisers to pay money to have their listings ranked higher in search results. Those search engines which do not accept money for their search engine results make money by running search related ads alongside the regular search engine results. The search engines make money every time someone clicks on one of these ads. The vast majority of search engines are run by private companies using proprietary algorithms and closed databases, though [[List of search engines#Open source search engines|some]] are open source.{{Fact|date=February 2007}} Revenue in the web search portals industry is projected to grow in 2008 by 13.4 percent, with broadband connections expected to rise by 15.1 percent. Between 2008 and 2012, industry revenue is projected to rise by 56 percent as Internet penetration still has some way to go to reach full saturation in American households. Furthermore, broadband services are projected to account for an ever increasing share of domestic Internet users, rising to 118.7 million by 2012, with an increasing share accounted for by fiber-optic and high speed cable lines.[http://www1.ibisworld.com/pressrelease/pressrelease.aspx?prid=115: March 2008, The Recession List – Top 10 Industries To Fly And Flop In 2008], ''IBISWorld'' ==See also==
*[[Index (search engine)]] *[[List of search engines]] *[[Local search (Internet)]] *[[Metasearch engine]] *[[OpenSearch]] *[[Search engine marketing]] *[[Search engine optimization]] *[[Search oriented architecture]] *[[Semantic Web]] *[[Social search]] *[[Spell checker]] *[[Web indexing]] *[[Web search query]] *[[Website Parse Template]]
==References== ===Notes=== The footnotes below are given in support of the statements above. Because some facts are proprietary secrets held by private companies and therefore not documented in journals, such facts are reasoned from facts that are public. :* GBMW: Reports of 30-day punishment, re: Car maker BMW had its German website bmw.de delisted from Google, such as: [http://slashdot.org/article.pl?sid=06/02/05/235218 Slashdot-BMW] (05-Feb-2006). :* INSIZ: Maximum size of webpages indexed by MSN/Google/Yahoo! ("100-kb limit"): [http://www.sitepoint.com/article/indexing-limits-where-bots-stop Max Page-size] (28-Apr-2006). {{reflist}} ===Bibliography=== * For a more detailed history of early search engines, see [http://searchenginewatch.com/showPage.html?page=3071951 Search Engine Birthdays] (from [[Search Engine Watch]]), Chris Sherman, September 2003. * {{cite journal | quotes = | author = Steve Lawrence; C. Lee Giles | date = | year = 1999| month = | title = Accessibility of information on the web | journal = [[Nature (journal)|Nature]] | volume = 400 | issue = | pages = 107 | doi = 10.1038/21987 }} * {{cite book | first = Mark | last = Levene | date = 2005 | title = An Introduction to Search Engines and Web Navigation | publisher = Pearson | location = | isbn = }} * {{cite book | first = Randolph | last = Hock | date = 2007 | title = The Extreme Searcher's Handbook}} ISBN 978-0-910965-76-7 * {{cite journal | quotes = | author = Javed Mostafa | date = | year = 2005 | month = February | title = Seeking Better Web Searches | journal = [[Scientific American Magazine]] | volume = | issue = | pages = | publisher = | location = | issn = | pmid = | doi = | bibcode = | oclc = | id = | url = http://www.sciam.com/article.cfm?articleID=0006304A-37F4-11E8-B7F483414B7F0000 | language = }} *{{cite journal |last=Ross |first=Nancy |authorlink= |coauthors=Wolfram, Dietmar |year=2000 |month= |title=End user searching on the Internet: An analysis of term pair topics submitted to the Excite search engine |journal=Journal of the American Society for Information Science |volume=51 |issue=10 |pages=949–958 |doi= |url= |accessdate= |quote= }} *{{cite journal |last=Xie |first=M. |authorlink= |coauthors=''et al.'' |year=1998 |month= |title=Quality dimensions of Internet search engines |journal=Journal of Information Science |volume=24 |issue=5 |pages=365–372 |doi=10.1177/016555159802400509 |url= |accessdate= |quote= }} ===External links=== * {{Dmoz|Computers/Internet/Searching/Search_Engines/|Search Engines}} * [http://www.searchenginehistory.com/ History of Search Engines] * [http://espace.library.uq.edu.au/view/UQ:124078 Research Quality, Publications and Impact in Civil Engineering into the 21st Century. Publish or Perish, Commercial versus Open Access, Internet versus Libraries ?] ''Canadian Journal of Civil Engineering'', 34 8: 946-951, 2007. * [http://espace.library.uq.edu.au/view.php?pid=UQ:23573 Impact of Commercial Search Engines and International Databases on Engineering Teaching and Research], European Journal of Engineering Education, 32 3: 261-269, 2007. [[Category:Information retrieval]] [[Category:Internet search engines| ]] [[Category:Internet terminology]] [[af:Soekenjin]] [[ar:محرك بحث]] [[bs:Internet pretraživač]] [[bg:Търсачка]] [[ca:Motor de recerca]] [[cs:Internetový vyhledávač]] [[da:Søgemaskine]] [[de:Suchmaschine]] [[el:Μηχανή αναζήτησης]] [[es:Motor de búsqueda]] [[eo:Serĉilo]] [[ext:Landeru]] [[eu:Bilaketa motor]] [[fa:جویشگر]] [[fr:Moteur de recherche]] [[gl:Motor de busca]] [[ko:검색 엔진]] [[hr:Tražilica]] [[id:Mesin pencari]] [[ia:Mechanismo de recerca]] [[it:Motore di ricerca]] [[he:מנוע חיפוש]] [[lv:Meklētājprogramma]] [[hu:Keresőmotor]] [[mk:Интернет пребарувач]] [[ms:Enjin gelintar]] [[nl:Zoekmachine]] [[ja:検索エンジン]] [[no:Søkemotor]] [[nn:Søkemotor]] [[uz:Veb qidiruv tizimi]] [[pl:Wyszukiwarka internetowa]] [[pt:Motor de busca]] [[ro:Motor de căutare]] [[ru:Поисковая система]] [[scn:Muturi di circata]] [[simple:Search engine]] [[sr:Интернет претраживач]] [[fi:Hakukone]] [[sv:Söktjänst]] [[ta:தேடுபொறி]] [[th:เสิร์ชเอนจิน]] [[vi:Máy truy tìm dữ liệu]] [[tr:Arama motoru]] [[uk:Пошукова система]] [[zh:搜索引擎]]