Google search

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Google
Google Search homepage
The Google homepage in Safari
URL www.google.com
list of domain names
Alexa rank #2
Commercial? yes
Type of site Search Engine
Registration optional
Available language(s) multilingual (~100)
Owner Google Inc.
Created by Larry Page & Sergey Brin
Launched September 15, 1997[1]
Revenue from AdWords
Current status active

Google is a search engine owned by Google, Inc. The largest search engine on the web, Google indexes a portion of the total amount of webpages on the web. Google receives several hundred million queries each day through its various services.

Contents

Main article: PageRank

Google uses a patented algorithm called PageRank to rank web pages that match a given search string. The PageRank algorithm computes a recursive figure of merit for web pages, based on the weighted sum of the PageRanks of the pages linking to them. The PageRank derives from human-generated links, and correlates well with human concepts of importance. Such concepts and linking criteria are part of the patented information that is not fully disclosed to users. The exact percentage of the total of web pages that google indexes is also not know as its very hard to actually calculate it.Previous keyword-based methods of ranking search results, used by many search engines that were once more popular than Google, would rank pages by how often the search terms occurred in the page, or how strongly associated the search terms were within each resulting page. In addition to PageRank, Google also uses other secret criteria for determining the ranking of pages on result lists.

Google not only indexes and caches (X)HTML files but also 13 other file types, which include PDF, Word documents, Excel spreadsheets, Flash SWF, plain text files, among others.[citation needed] Except in the case of text and SWF files, the cached version is a conversion to (X)HTML, allowing those without the corresponding viewer application to read the file.

Users can customize the search engine somewhat. They can set a default language, use "SafeSearch" filtering technology (which is on 'moderate' setting by default), and set the number of results shown on each page. Google has been criticized for placing long-term cookies on users' machines to store these preferences, a tactic which also enables them to track a user's search terms over time. It retains data for more than a year.[citation needed] For any query (of which only the 32 first keywords are taken into account), up to the first 1000 results can be shown with a maximum of 100 displayed per page.

Google's searches are not limited to reporting back indexed pages corresponding to the search query. A variety of advanced search operators can be used to perform more sophisticated queries. Some examples are included below:

  • link: - returns the pages linking to the specified URL.
  • site: - restricts the returned hits to a specific website.
  • define: - returns Google glossary definition for the query term.
  • info: - returns information about the queried page.
  • filetype: - restrict the results of the search to a particular filetype extension e.g. doc, txt, jpg.
  • related: - returns similar / related webpages.
  • date: - returns only those results posted within the last 'date' months (or within a range of dates).
  • safesearch: - excludes adult-content from search results

A full listing of Google's advanced operators can be located here [2][3].

Search parameters or modifiers are included in a search URL to modify search results. Some examples of search parameters include[4]:

  • q= - contains the search query.
  • hl= - specifies the interface language.
  • lr= - language restrict: restricts the search to the specified language(s).
  • num= - number of results displayed in each page.
  • newwindow= - opens the result in a new window.
  • as_filetype= - specifies the filetype (e.g., pdf, doc, xml).
  • filter= - causes Google to filter search results.
  • safe= - turns safe search filtering on or off.
  • gl= - geographic localization (country).
  • gll= - geographic localization (latitude&longitude).
  • btnI - "I'm feeling lucky" button.
  • btnG - normal Google Search button.

Google also lists some of its search parameters here: [5].

Despite its immense index, there is also a considerable amount of data in databases, which are accessible from websites by means of queries, but not by links. This so-called deep web is minimally covered by Google and contains, for example, catalogs of libraries, official legislative documents of governments, phone books, and more.

Since Google is the most popular search engine, many webmasters have become eager to influence their website's Google rankings. An industry of consultants has arisen to help websites raise their rankings on Google and on other search engines. This field, called search engine optimization, attempts to discern patterns in search engine listings, and then develop a methodology for improving rankings.

As Google's algorithms and results have gained the trust of web users, commercial websites will profit from subverting these results by artificially inflating their rankings. Some search engine optimization firms have attempted to inflate specific Google rankings by various artifices, and thereby draw more searchers to their client's sites. One of Google's main challenges has been to weaken some of these attempts by reducing the ranking of sites known to use them.

Search engine optimization encompasses both "on page" factors (like body copy, title tags, H1 heading tags and image alt attributes) and "Off Page Optimisation" factors (like anchor text and PageRank). The general idea is to affect Google's relevance algorithm by incorporating the keywords being targeted in various places "on page", in particular the title tag and the body copy (note: the higher up in the page, the better its keyword prominence and thus the ranking). Too many occurrences of the keyword, however, cause the page to look suspect to Google's spam checking algorithms.

One "Off Page Optimisation" technique that works particularly well is Google Adwords in which websites link to another site using a particular phrase in the anchor text, in order to give the site a high ranking when the word is searched for.

The Google webmaster guidelines were published for website owners who would like to raise their rankings when using legitimate optimization consultants.[6]

A corollary use of Google — and other Internet search engines — is that it can help translators to determine the most common way of expressing ideas in the English language (and other languages). This is generally done by doing a 'count' of different variants, thereby establishing which expression is more common. While this approach requires careful judgment, it does improve the ability of non-native translators to use more idiomatically correct English expressions. Google is also quickly becoming the 'big brother' of the world, logging and recording what ever and whenever someone logs onto any of their subsidiaries.

Google dance refers to the period of time when Google indices are tuned. This will often cause both a fluctuation in index size as well a significant change in a web site's search result position.

Besides the main search engine feature of searching for text, the search engine can be used as a calculator, currency converter, dictionary and many other useful tools.

Some searches will give a 403 Forbidden error with the text

"We're sorry... ... but your query looks similar to automated requests from a computer virus or spyware application. To protect our users, we can't process your request right now. We'll restore your access as quickly as possible, so try again soon. In the meantime, if you suspect that your computer or network has been infected, you might want to run a virus checker or spyware remover to make sure that your systems are free of viruses and other spurious software. We apologize for the inconvenience, and hope we'll see you again on Google."

followed by a CAPTCHA prompt.[7]

The suggestion that the user's computer may be infected is often incorrect.[citation needed] The screen was first reported in 2005 and was a response to the heavy use of Google by Search Engine Optimisation companies to check on ranks of sites they were optimising. The message may also be triggered by high volumes of different searches from a single IP address. The block is removed after a day.[citation needed]

Google is available in many languages and has been localized for many countries[8].

The interface has also been made available in fake languages for humorous purpose:

In addition to the main URL Google.com, Google owns 160 domain names for each of the countries/regions in which is has been localized.[8] As Google is an American company, the main domain name can be considered as the U.S. one though the gTLD .com can be used by any company in the world (not only those from the United States). Google.us does exist but is only a redirection to google.com because dot-US is by far less common than dotcom in the United States. An example is Google.ca

List of domain names

Main article: List of Google products

In addition to its tool for searching webpages, Google also provides services for searching images, Usenet newsgroups, news websites, videos, searching by locality, maps, and items for sale online. In 2006, Google has indexed over 25 billion web pages, 1.3 billion images, and over one billion Usenet messages.[citation needed] It also caches much of the content that it indexes. Google operates other tools and services including Google News, Google Suggest, Froogle, Google Maps, Google Co-op and Google Desktop Search.

There are also products available from Google that are not directly search-related. Gmail, for example, is a webmail application, but still include search features; Google Browser Sync does not offer any search facilities, although it aims to organise your browsing time.

  1. ^ WHOIS - google.com. Retrieved on 2007-08-10.
  2. ^ Search strategies
  3. ^ Google Advanced Operators Cheat Sheet
  4. ^ Google Websearch Parameters
  5. ^ Google Search Request Format
  6. ^ Google Webmaster Guidelines
  7. ^ Google error page. Retrieved on 2007-12-16.
  8. ^ a b http://www.google.com/language_tools?hl=en

  • Google Hacks from O'Reilly is a book containing tips about using Google effectively. Now in its third edition. ISBN 0-596-52706-3.
  • Google: The Missing Manual by Sarah Milstein and Rael Dornfest (O'Reilly, 2004). ISBN 0-596-00613-6
  • How to Do Everything with Google by Fritz Schneider, Nancy Blachman, and Eric Fredricksen (McGraw-Hill Osborne Media, 2003). ISBN 0-07-223174-2
  • Google Power by Chris Sherman (McGraw-Hill Osborne Media, 2005). ISBN 0-07-225787-3
  • SEO for Google by Paul Bliss - an eBook that describes in precise detail the methods needed to get your site top rankings in Google for your keywords.

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