A search engine lists web pages on the Internet

A search engine lists web pages on the Internet. This facilitates research by offering an immediate variety of applicable options. Possibly useful items on the results list include the source material or the electronic tools that a web site can provide, such as a dictionary, but the list itself, as a whole, can also indicate important information. However, discerning that information may require insight.Referencing search engine results is a quick way to either present (what is notable) or delete (what is not verifiable) source material, depending on their reliability. There is a high demand for reliability on Wikipedia. Discerning the reliability of the source material is an especially core skill for using the web, while the wiki itself only facilitates the creation multiple drafts. As presentations and deletions progress, this variety of choices for input tend to produce the desired objective—a neutral viewpoint. Depending on the type of query and kind of search engine, this variety can open up to a single author.Some search engine tests:This page describes both these web search tests and the web search tools that can help develop Wikipedia, and it describes their biases and their limitations.The advantages of a specific search engine can be distinguished by using a variety of common search engines. The distinct advantages of each are their user interface and, less obviously, their algorithms for compiling and searching their own indexes. Because a web crawler can be blocked—specific ones or just in general—different search engines can list different web sites, and there are more web sites available by URL than are indexed in any database.The most common search engines are at Google, Bing, and Yahoo. Specialized search engines exist for medicine, science, news and law amongst others. Several generalized search engines exist. These adapt your query to many search engines. See Common search engines below. This page mostly uses Google instead of Bing or Yahoo, but aims for generality where it can. For example, it describes Google Groups (usenet groups), Google scholar (academia), Google news, and Google books.If an unsourced addition to an article appears plausible, consider taking a moment to use Google (or some other search engine) to find a reliable source before deciding whether to revert.Depending on the subject matter, and how carefully it is used, a search engine test can be very effective and helpful, or produce misleading or non-useful results. In most cases, a search engine test is a first-pass heuristic or "rule of thumb".A search engine can index pages and text which others have placed on the internet, just like a big index at the back of a book.Search engines can:Search engines cannot:and search engines often will not:A search engine test cannot help you avoid the work of interpreting your results and deciding what they really show. Appearance in an index alone is not usually proof of anything.Search engine tests may return results that are fictitious, biased, hoaxes or similar. It is important to consider whether the information used derives from reliable sources before using or citing it. Less reliable sources may be unhelpful, or need their status and basis clarified, so that other readers gain a neutral and informed understanding to judge how reliable the sources are.Google (and other search systems) do not aim for a neutral point of view. Wikipedia does. Google indexes self-created pages and media pages which do not have a neutrality policy. Wikipedia has a neutrality policy that is mandatory and applies to all articles, and all article-related editorial activity.As such, Google is specifically not a source of neutral titles – only of popular ones. Neutrality is mandatory on Wikipedia (including deciding what things are called) even if not elsewhere, and specifically, neutrality trumps popularity.Raw "hit" (search result) count is a very crude measure of importance. Some unimportant subjects have many "hits", some notable ones have few or none, for reasons discussed further down this page.Hit count numbers alone can only rarely "prove" anything about notability, without further discussion of the type of hits, what's been searched for, how it was searched, and what interpretation to give the results. On the other hand, examining the types of hit arising (or their lack) often does provide useful information related to notability.Additionally, search engines do not disambiguate, and tend to match partial searches. (However, as described below, you can eliminate partial matches by quoting the phrase to be matched): While Madonna of the Rocks is certainly an encyclopedic and notable entry, it's not a pop culture icon. However, due to Madonna matching as a partial match, as well as other Madonna references not related to the painting, the results of a Google or Bing search result count will be disproportionate as compared to any equally notable Renaissance painting. To exclude partial matches when Googling for the phrase, quote the phrase to be matched as follows: "Madonna of the Rocks".The single most useful search engine tool may be the use of quotation marks to find an exact match for a phrase. However, a search engine such as Google has both an easy, and an advanced search with further search options. The advanced search makes it easier to enter advanced options, that may help your searching. The following collapsible sections cover basic examples and help for using search engines with Wikipedia.Specialized search engines such as medical paper archives have their own specialized search structure not covered here.Two variations are shown; one looks for the expression "George Bush", and one has a second exclusion to rule out pages with the term "white house"This search looks for pages that contain references to Linux, references to the two most common boot loaders ("grub" or "lilo"), references to start-up under three common terms that might be used, and other words that hopefully will be commonly related to start-up in Linux.If this text is copied from a website, a search like this will often help to locate the source.(This is a good way to avoid a deluge of results which are all either from Wikipedia, or from copies and mirrors of Wikipedia articles.)Simply click the template-generated link then add the positive and negative match terms "tennis" and "-tenis" to the search string and repeat the search.Site inclusion/exclusion is often very useful to get views either from a named website, or from any other websites. For example, it can be usedSpecialized searches work on the same principles and same basic search expressions as the above, but might be used to check in specialized archives, or with unusual options.A raw hit count should never be relied upon to prove notability. Attention should instead be paid to what (the books, news articles, scholarly articles, and web pages) is found, and whether they actually do demonstrate notability or non-notability, case by case. Hit counts have always been, and very likely always will remain, an extremely erroneous tool for measuring notability, and should not be considered either definitive or conclusive. A manageable sample of results found should be opened individually and read, to actually verify their relevance.In the case of Google (and other search engines such as Bing and Yahoo!), the hit count at the top of the page is unreliable and should usually not be reported. The hit count reported on the penultimate (second-to-last) page of results may be slightly more accurate. For searches with few reported hits (less than 1000) the actual count of hits needed to reach the bottom of the last page of results may be more accurate, but even this is not a sure thing. Google returns different search results depending on factors such as your previous search history and on which Google server you happen to hit. [8] [9]Other useful considerations in interpreting results are:In most cases, search results should be reviewed with an awareness and careful skepticism before relying upon them. Common biases include:In some cases, it is helpful to estimate the relative popularity of a website. Alexa Internet is a tool for this (Hitwise and Quantcast are others). To test Alexa's ranking for a particular web site, visit alexa.com and enter the URL.The Alexa measuring system is based on a toolbar that users must choose to install, which can be installed on several browsers including Internet Explorer and Mozilla Firefox, across different operating systems. Sources of bias include both websites whose users disproportionately do not install such toolbars, as well as webmasters who install Alexa Toolbar for the sole purpose of enhancing their ratings. Specifically, Alexa rankings are not part of the notability guidelines for web sites for several reasons:Often for items of non-English origin, or in non-Latin scripts, a considerably larger number of hits result from searching in the correct script or for various transcriptions—be sure to check "Languages for Displaying (Search) Results" in "Search Settings".[4] An Arabic name, for instance, needs to be searched for in the original script, which is easily done with Google (provided one knows what to search for), but problems may arise if – for example – English, French and German webpages transcribe the name using different conventions. Even for English-only webpages there may be many variants of the same Arabic or Russian name. Personal names in other languages (Russian, Anglo-Saxon) may have to be searched for both including and excluding the patronymic, and searches for names and other words in strongly inflected languages should take into account that arriving at the total number of hits may require searching for forms with varying case-endings or other grammatical variations not obvious for someone who does not know the language. Names from many cultures are traditionally given together with titles that are considered part of the name, but may also be omitted (as in Gazi Mustafa Kemal Pasha).Even in Old English, the spelling and rendering of older names may allow dozens of variations for the same person. A simplistic search for one particular variant may underrepresent the web presence by an order of magnitude.A search like this requires a certain linguistic competence which not every individual Wikipedian possesses, but the Wikipedia community as a whole includes many bilingual and multilingual people and it is important for nominators and voters on AfD at least to be aware of their own limitations and not make untoward assumptions when language or transcription bias may be a factor.Note also, that the number of search string matches reported by search engines is only an estimate. For example, Google will only calculate the actual number of matches once the user navigates through all result pages, to the last one, and even then it places restrictions on the figure. At times, the "match" count estimate can be significantly different (by one or more orders of magnitude) to the total count of results shown on the last results page.A site-specific search may help determine if most of the matches are coming from the same web site; a single web site can account for hundreds of thousands of hits.For search terms that return many results, Google uses a process that eliminates results which are "very similar" to other results listed, both by disregarding pages with substantially similar content and by limiting the number of pages that can be returned from any given domain. For example, a search on "Taco Bell" will give only a couple of pages from tacobell.com even though many in that domain will certainly match. Further, Google's list of distinct results is constructed by first selecting the top 1000 results and then eliminating duplicates without replacements. Hence the list of distinct results will always contain fewer than 1000 results regardless of how many webpages actually matched the search terms. For example, from the about 742 million pages related to "Microsoft", Google presently returns 572 "distinct" results (as of 14 December 2010[update][11]). Caution must be used in judging the relative importance of websites yielding well over 1000 search results.Many, probably most, of the publicly available web pages in existence are not indexed. Each search engine captures a different percentage of the total. Nobody can tell exactly what portion is captured.The estimated size of the World Wide Web is at least 11.5 billion pages,[12] but a much deeper (and larger) Web, estimated at over 3 trillion pages, exists within databases whose contents the search engines do not index. These dynamic web pages are formatted by a Web server when a user requests them and as such cannot be indexed by conventional search engines. The United States Patent and Trademark Office website is an example; although a search engine can find its main page, one can only search its database of individual patents by entering queries into the site itself.[13]Google, like all Internet search engines can only find information that has actually been made available on the Internet. There is still a sizable amount of information that is not on the Internet.Google, as all search engines should, follows the robots.txt protocol and can be blocked by sites that do not wish their content to be indexed or cached by Google. Sites that contain large amounts of copyrighted content (Image galleries, subscription newspapers, webcomics, movies, video, help desks), usually involving membership, will block Google and other search engines. Other sites may also block Google due to the stress or bandwidth concerns on the server hosting the content.Search engines also might not be able to read links or metadata that normally requires a browser plugin, Adobe PDF, or Macromedia Flash, or where a website is displayed as part of an image. Search engines also can not listen to podcasts or other audio streams, or even video mentioning a search term. Similarly search engines cannot read PDF files consisting of photoscans or look inside compressed (.zip) files.Forums, membership-only and subscription-only sites (since Googlebot does not sign up for site access) and sites that cycle their content are not cached or indexed by any search engine. With more sites moving to AJAX/Web 2.0 designs, this limitation will become more prevalent as search engines only simulate following the links on a web page. AJAX page setups (like Google Maps) dynamically return data based on realtime manipulation of Javascript.Google has also been the victim of redirection exploits that may cause it to return more results for a specific search term than exist actual content pages.Google and other popular search engines are also a target for search engine "search result enhancement", also known as search engine optimizers, so there may also be many results returned that lead to a page that only serves as an advertisement. Sometimes pages contain hundreds of keywords designed specifically to attract search engine users to that page, but in fact serve an advertisement instead of a page with content related to the keyword.Hit counts reported by Google are only estimates, which in some cases have been shown to necessarily be off by nearly an order of magnitude, especially for hit counts above a few thousands.[14][15] For such common words as to yield several thousand Google hits, freely available text corpora such as the British National Corpus (for British English) and the Corpus of Contemporary American English (for American English) can provide a more accurate estimate of the relative frequencies of two words.The Economic Crime Summit site is a rather Google- and Internet Archive-unfriendly site. It is very graphics heavy, providing Google with little to nothing to look for and many missing pages in the Internet Archive version. So while you can bring up the 2002 Economic Crime Summit Conference, the overview link that would tell you who presented what does not work. The 2004 Economic Crime Summit Conference archive is even worse as that was in three places and none of the archived links tells you anything about the papers presented.Via Internet Archive you have proof that some information regarding "Impact of Advances in Computer Technology in Evidence Processing" existed on the Internet[16]. Yet today Google cannot find that information! A program known to be part of the 2002 Economic Crime Summit Conference and at one time was listed on a website on the Internet currently cannot be found by Google.The most common search engines are Google, Bing, and Yahoo, but the most useful search engine, which depend on a context, may not be the most common ones.Google groups archives Usenet. Because it covers over twenty years, it one of the oldest archives on record, going back to the beginning of the web.Google Scholar works well for fields that are paper-oriented and have an online presence in all (or nearly all) respected venues. This search engine is a good complement for the commercially available Thompson ISI Web of Knowledge, especially in the areas which are not well covered in the latter, including books, conference papers, non-American journals, the general journals in the field of strategy, management, international business,[17] English language education and educational technology.[18] The analysis of the PageRank algorithm utilised by Google Scholar demonstrated that this search engine, as well as its commercial analogs, provides an adequate information about popularity of some concrete source,[19] although that does not automatically reflect the real scientific contribution of concrete publication.[19]Medline, now part of Pubmed, is the original broadly based search engine, originating over four decades ago and indexing even earlier papers. Thus, especially in biology and medicine, Pubmed "associated articles" is a Google Scholar proxy for older papers with no on-line presence. E.g., The journal Stroke puts papers on-line back through 1970s. For this 1978 paper [2], Google Scholar lists 100 citing articles, while Pubmed lists 89 associated articlesThere are a large number of law libraries online, in many countries, including: Library of Congress, Library of Congress (THOMAS), Indiana Supreme Court, FindLaw (USA); Kent University Law Library and sources (UK).See also this list of search engines.Several generalized search engines exist. These adapt your query to many search engines. Web browsers offer a choice of search engines to choose to employ for the search box, and these can be used one at a time to experiment with search results. Meta-search engines use several search engines at once. Ten popular ones from About.com offer reviews. A web browser plugin can add a search engine or a meta-search engine to your list of choices.