A meta-search engine is a search Information retrieval is the science of searching for documents, for information within documents and for metadata about documents, as well as that of searching relational databases and the World Wide Web. There is overlap in the usage of the terms data retrieval, document retrieval, information retrieval, and text retrieval, but each also has its tool[1] that sends user requests to several other search engines and/or databases and aggregates the results into a single list or displays them according to their source. Metasearch engines enable users to enter search criteria once and access several search engines simultaneously. Metasearch engines operate on the premise that the Web The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. Using concepts from earlier hypertext systems, English physicist Tim Berners-Lee, now the Director of the is too large for any one search engine to index it all and that more comprehensive search results can be obtained by combining the results from several search engines. This also may save the user from having to use multiple search engines separately.

The term Metasearch is frequently used to classify a set of commercial search engines, see the list of search engines This is a list of Wikipedia articles about search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites that have a search facility for online databases, but is also used to describe the paradigm of searching multiple data sources in real time. The National Information Standards Organization (NISO The National Information Standards Organization is a United States non-profit standards organization that develops, maintains and publishes technical standards related to publishing, bibliographic and library applications. It was founded in 1939, incorporated as a not-for-profit education association in 1983, and assumed its current name in 1984) uses the terms Federated Search Federated search is the simultaneous search of multiple online databases or web resources and is an emerging feature of automated, web-based library and information retrieval systems. It is also often referred to as a portal or a federated search engine and Metasearch interchangeably to describe this web search paradigm.

Contents

Operation

architecture of a metasearch engine

Metasearch engines create what is known as a virtual database. They do not compile a physical database One way of classifying databases involves the type of content, for example: bibliographic, full-text, numeric, image. Other classification methods start from examining database models or database architectures: see below or catalogue of the web. Instead, they take a user's request, pass it to several other heterogeneous Heterogeneous is an adjective used to describe an object or system consisting of multiple items having a large number of structural variations. It is the opposite of homogeneous, which means that an object or system consists of multiple identical items. The term is often used in a scientific , mathematical, sociological or statistical context databases and then compile the results in a homogeneous manner based on a specific algorithm In mathematics, computing, linguistics, and related subjects, an algorithm is an effective method for solving a problem using a finite sequence of instructions. Algorithms are used for calculation, data processing, and many other fields.

No two metasearch engines are alike. Some search only the most popular search engines while others also search lesser-known engines, newsgroups A usenet newsgroup is a repository usually within the Usenet system, for messages posted from many users in different locations. The term may be confusing to some, because it is usually a discussion group. Newsgroups are technically distinct from, but functionally similar to, discussion forums on the World Wide Web. Newsreader software is used to, and other databases. They also differ in how the results are presented and the quantity of engines that are used. Some will list results according to search engine or database. Others return results according to relevance, often concealing which search engine A web search engine is a tool designed to search for information on the World Wide Web. The search results are usually presented in a list and are commonly called hits. The information may consist of web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike Web returned which results. This benefits the user by eliminating duplicate hits and grouping the most relevant ones at the top of the list.

Search engines frequently have different ways they expect requests submitted. For example, some search engines allow the usage of the word "AND" while others require "+" and others require only a space to combine words. The better metasearch engines try to synthesize requests appropriately when submitting them[citation needed].

Quality of results

Results can vary between metasearch engines based on a large number of variables. Still, even the most basic metasearch engine will allow more of the web to be searched at once than any one stand-alone search engine. On the other hand, the results are said[who?] to be less relevant, since a metasearch engine can’t know the internal “alchemy” a search engine does on its result (a metasearch engine does not have any direct access to the search engines’ database).

Metasearch engines are sometimes used in vertical search Vertical search, or domain-specific search, part of a larger sub-grouping known as "specialized" search, is a relatively new tier in the Internet search industry, consisting of search engines that focus on specific slices of content. The type of content in special focus may be based on topicality or information type. For example, an portals, and to search the deep web The deep Web refers to World Wide Web content that is not part of the surface Web, which is indexed by standard search engines[citation needed].

See also

For engines, see the list of search engines This is a list of Wikipedia articles about search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites that have a search facility for online databases

References

  1. ^ Sandy Berger's Great Age Guide to the Internet By Sandy Berger. Que Publishing, 2005. ISBN 0789734427.

External links

Internet search
Types Web search engine A web search engine is a tool designed to search for information on the World Wide Web. The search results are usually presented in a list and are commonly called hits. The information may consist of web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike Web (List This is a list of Wikipedia articles about search engines, including web search engines, selection-based search engines, metasearch engines, desktop search tools, and web portals and vertical market websites that have a search facility for online databases) · Collaborative search engine · Metasearch engine
Tools Local search Local search is the use of specialized Internet search engines that allow users to submit geographically constrained searches against a structured database of local business listings. Typical local search queries include not only information about "what" the site visitor is searching for but also "where" information, such as a · Vertical search Vertical search, or domain-specific search, part of a larger sub-grouping known as "specialized" search, is a relatively new tier in the Internet search industry, consisting of search engines that focus on specific slices of content. The type of content in special focus may be based on topicality or information type. For example, an · Search engine marketing Search engine marketing, or SEM, is a form of Internet marketing that seeks to promote websites by increasing their visibility in search engine result pages through the use of paid placement, contextual advertising, and paid inclusion.. The industry peak body Search Engine Marketing Professional Organization (SEMPO) founded by Barbara Coll in 2003, · Search engine optimization Search engine optimization is the process of improving the volume or quality of traffic to a web site from search engines via "natural" or un-paid ("organic" or "algorithmic") search results as opposed to search engine marketing (SEM) which deals with paid inclusion. Typically, the earlier (or higher) a site appears · Search oriented architecture The use of search engine technology as the main integration component in an information system. In a traditional business environment the architectural layer usually occupied by a relational database management system is supplemented or replaced with a search engine or the indexing technology used to build search engines. Queries for information · Selection-based search A selection-based search system is a search engine system in which the user invokes a search query using only the mouse. A selection-based search system allows the user to search the internet for more information about any keyword or phrase contained within a document or webpage in any software application on his desktop computer using the mouse · Social search Social search or a social search engine is a type of web search method that determines the relevance of search results by considering the interactions or contributions of users. When applied to web search this user-based approach to relevance is in contrast to established algorithmic or machine-based approaches where relevance is determined by · Document retrieval Document retrieval is defined as the matching of some stated user query against a set of free-text records. These records could be any type of mainly unstructured text, such as newspaper articles, real estate records or paragraphs in a manual. User queries can range from multi-sentence full descriptions of an information need to a few words · Text mining Text mining, sometimes alternately referred to as text data mining, roughly equivalent to text analytics, refers generally to the process of deriving high-quality information from text. High-quality information is typically derived through the divining of patterns and trends through means such as statistical pattern learning. Text mining usually · Web crawler A Web crawler is a computer program that browses the World Wide Web in a methodical, automated manner. Other terms for Web crawlers are ants, automatic indexers, bots, and worms or Web spider, Web robot, or—especially in the FOAF community—Web scutter · Multisearch Multisearch is a multitasking search engine which includes both search engine and metasearch engine characteristics with additional capability of retrieval of search result sets that were previously classified by users. It enables the user to gather results from its own search index as well as from one or more search engines, metasearch engines, · Federated search Federated search is the simultaneous search of multiple online databases or web resources and is an emerging feature of automated, web-based library and information retrieval systems. It is also often referred to as a portal or a federated search engine · Search aggregator A search aggregator is a type of metasearch engine which gathers results from multiple search engines simultaneously through RSS search results. It combines user specified search feeds to give the user the same level of control over content as a general aggregator · Index Search engine indexing collects, parses, and stores data to facilitate fast and accurate information retrieval. Index design incorporates interdisciplinary concepts from linguistics, cognitive psychology, mathematics, informatics, physics and computer science. An alternate name for the process in the context of search engines designed to find web/Web indexing Web indexing includes back-of-book-style indexes to individual websites or an intranet, and the creation of keyword metadata to provide a more useful vocabulary for Internet or onsite search engines. With the increase in the number of periodicals that have articles online, web indexing is also becoming important for periodical websites · Focused crawler A focused crawler or topical crawler is a web crawler that attempts to download only web pages that are relevant to a pre-defined topic or set of topics. Topical crawling generally assumes that only the topic is given, while focused crawling also assumes that some labeled examples of relevant and not relevant pages are available. Topical crawling · Spider trap A spider trap is a set of web pages that may intentionally or unintentionally be used to cause a web crawler or search bot to make an infinite number of requests or cause a poorly constructed crawler to crash. Web crawlers are also called web spiders, from which the name is derived. Spider traps may be created to "catch" spambots or · Robots exclusion standard The Robot Exclusion Standard, also known as the Robots Exclusion Protocol or robots.txt protocol, is a convention to prevent cooperating web spiders and other web robots from accessing all or part of a website which is otherwise publicly viewable. Robots are often used by search engines to categorize and archive web sites, or by webmasters to · Distributed web crawling Distributed web crawling is a distributed computing technique whereby Internet search engines employ many computers to index the Internet via web crawling. The idea is to spread out the required resources of computation and bandwidth to many computers and networks · Web archiving Web archiving is the process of collecting portions of the World Wide Web and ensuring the collection is preserved in an archive, such as an archive site, for future researchers, historians, and the public. Due to the massive size of the Web, web archivists typically employ web crawlers for automated collection. The largest web archiving · Website mirroring software Website mirroring software is software that allows one to download a copy of an entire website to the local hard disk for offline browsing. In effect, the downloaded copy serves as a mirror of the original site · Web search query A web search query is a query that a user enters into web search engine to satisfy his or her information needs. Web search queries are distinctive in that they are unstructured and often ambiguous; they vary greatly from standard query languages which are governed by strict syntax rules · Voice search Voice search, also called voice-enabled search, allows the user to use a voice command to search the Internet, or a portable device. Currently, voice search is commonly used in "directory assistance", or local search. Examples include Google 411, Tellme directory assistance and Yellowpages.com's 1-800-YellowPages. In a broader definition, · Human flesh search engine Human Flesh Search is a phenomenon of massive researching using Internet media such as blogs and forums. It is based on massive human collaboration, thus the name · Natural language search engine A Natural language search engine is a search engine designed to search for information on the World Wide Web using techniques of Natural language processing, such as question answering. Natural language search is a major goal in the development of the semantic web · Web query classification Web query topic classification/categorization is a problem in information science. The task is to assign a Web search query to one or more predefined categories, based on its topics. The importance of query classification is underscored by many services provided by Web search. A direct application is to provide better search result pages for users
Applications Image search · Video search engine A video search engine is a web-based search engine which crawls the web for video content. Some video search engines parse externally hosted content while others allow content to be uploaded and hosted on their own servers. Some engines also allow users to search by video format type and by length of the clip. Search results are usually · Enterprise search The term "enterprise search" is used to describe the application of search technology to information within an organization . This is in contrast to the other two main types of horizontal search environment: web search and desktop search (though the areas overlap, and systems may address these scenarios as well) · Semantic search
Protocols and standards Z39.50 · Search/Retrieve Web Service · Search/Retrieve via URL · OpenSearch · Representational State Transfer ·
See also Search engine · Desktop search

Categories: Internet search engines

<<Table of Contents | Show All>>

 

The above information uses material from Wikipedia and is licensed under the GNU Free Documentation License.
Some facts may not have been fully verified for accuracy. [Disclaimers]
This page was last archived by our server on Fri Sep 25 10:28:59 2009. [ refresh local cache ]
Displaying this page or its contents does not use any Wikimedia Foundation's resources.
The owners of this site proudly support the Wikimedia Foundation.

[Hide]▼
[Hide]▲