Sunday, May 30, 2010
Saturday, May 29, 2010
"I'm Feeling Lucky"
Google's homepage includes a button labeled "I'm Feeling Lucky". When a user clicks on the button the user will be taken directly to the first search result, bypassing the search engine results page. The thought is that if a user is "feeling lucky", the search engine will return the perfect match the first time without having to page through the search results. According to a study by Tom Chavez of "Rapt", this feature costs Google $110 million a year as 1% of all searches use this feature and bypass all advertising.[17]
On October 30, 2009, for some users, the "I'm Feeling Lucky" button was removed from Google's main page, along with the regular search button. Both buttons were replaced with a field that reads, "This space intentionally left blank." This text fades out when the mouse is moved on the page, and normal search functionality is achieved by filling in the search field with the desired terms and pressing enter. A Google spokesperson explains, "This is just a test, and a way for us to gauge whether our users will like an even simpler search interface."[18] Personalized Google homepages retained both buttons and their normal functions.
On May 21, 2010, the 30th anniversary of Pac-Man, the "I'm Feeling Lucky" button was replaced with a button reading the words "Insert Coin". After pressing the button, the user would begin a Google-themed game of Pac-Man in the area where the Google logo would normally be. Pressing the button a second time would begin a two-player version of the same game that includes Ms. Pacman for player 2.
Query expansion
Google applies query expansion to the submitted search query, transforming it into the query that will actually be used to retrieve results. As with page ranking, the exact details of the algorithm Google uses are deliberately obscure, but certainly the following transformations are among those that occur:
- Term reordering: in information retrieval this is a standard technique to reduce the work involved in retrieving results. This transformation is invisible to the user, since the results ordering uses the original query order to determine relevance.
- Stemming is used to increase search quality by keeping small syntactic variants of search terms.[16]
- There is a limited facility to fix possible misspellings in queries.
Search syntax
Google's search engine normally accepts queries as a simple text, and breaks up the user's text into a sequence of search terms, which will usually be words that are to occur in the results, but may also be phrases, delimited by quotations marks ("), qualified terms, with a prefix such as "+", "-", or one of several advanced operators, such as "site:". The webpages of "Google Search Basics" describe each of these additional queries and options (see below: Search options).
Google's Advanced Search web form gives several additional fields which may be used to qualify searches by such criteria as date of first retrieval. All advanced queries transform to regular queries, usually with additional qualified terms.
Functionality
Google optimization
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 increase 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 to draw more searchers to their client's sites.
Search engine optimization encompasses both "on page" factors (like body copy, title elements, H1 heading elements and image alt attribute values) and Off Page Optimization 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 element and the body copy (note: the higher up in the page, presumably 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.
Google has published guidelines for website owners who would like to raise their rankings when using legitimate optimization consultants.[14]
Non-indexable data
Despite its immense index, there is also a considerable amount of data available in online databases which are accessible by means of queries but not by links. This so-called invisible or deep Web is minimally covered by Google and other search engines.[13] The deep Web contains library catalogs, official legislative documents of governments, phone books, and other content which is dynamically prepared to respond to a query.
Privacy in some countries forbids the showing of some links. For instance in Switzerland every private person can force Google Inc. to delete a link, which contains their name.[citation needed]
Search results
The exact percentage of the total of web pages that Google indexes is not known, as it is very hard to actually calculate. Google not only indexes and caches web pages but also takes "snapshots" of other file types, which include PDF, Word documents, Excel spreadsheets, Flash SWF, plain text files, and so on.[12] 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, by setting a default language, using the "SafeSearch" filtering technology 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 and retain the data for more than a year. For any query, up to the first 1000 results can be shown with a maximum of 100 displayed per page.
PageRank
what is google.com
Google Search or Google Web Search is a web search engine owned by Google Inc. and is the most-used search engine on the Web.[3] Google receives several hundred million queries each day through its various services.[4] The main purpose of Google Search is to hunt for text in webpages, as opposed to other data, such as with Google Image Search. Google search was originally developed by Larry Page and Sergey Brin in 1997.[5]
Google Search provides more than 22 special features beyond the original word-search capability.[6] These include synonyms, weather forecasts, time zones, stock quotes, maps, earthquake data, movie showtimes, airports, home listings, and sports scores. (see below:Special features ). There are special features for numbers, including ranges (70..73),[7] prices, temperatures, money/unit conversions ("10.5 cm in inches"), calculations ( 3*4+sqrt(6)-pi/2 ), package tracking, patents, area codes,[6] and rudimentary language translation of displayed pages.
The order of search results on Google's search-results pages is based on a priority rank called a "PageRank". Google Search provides many options for customized search