A metasearch engine is a search tool 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 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 Metasearch engine, but is also used to describe the paradigm of searching multiple data sources in real time. Operation architecture of a metasearch engine Search engines frequently have different ways they expect requests submitted. See also References
Related: Online Search Tools : Meta Search
Meta-Search Engines-The Library"Smarter" meta-searcher technology includes clustering and linguistic analysis that attempts to show you themes within results, and some fancy textual analysis and display that can help you dig deeply into a set of results. However, neither of these technologies is any better than the quality of the search engine databases they obtain results from. Few meta-searchers allow you to delve into the largest, most useful search engine databases. Although we respect the potential of textual analysis and clustering technologies, we recommend directly searching individual search engines to get the most precise results, and using meta-searchers if you want to explore more broadly. The meta-search tools listed here are "use at your own risk." Better Meta-Searchers Meta-Search Engines for SERIOUS Deep Digging CSEs: Make Your Own Meta-Search Engine Google Custom Search Engines (CSEs) focus on selected websites within the Google database. How Do You Find Custom Search Engines
Clustering EngineCarrot2 Search Results Clustering Engine Carrot2 organizes your search results into topics. With an instant overview of what's available, you will quickly find what you're looking for. Choose where to search: Type your query: More options More advanced options Hide advanced options Example queries: data mining | london | clustering About Carrot2: Carrot2 is an Open Source Search Results Clustering Engine.
List of social bookmarking websitesDefunct sites See also Notes and referencesGlobal - Find search engines from across the world with Search Engine ColossusToday | KillerStartups.com™Meta search engine | Mother of All Search Engines - Mamma.com100 Incredibly Useful and Interesting Web Sites - PCWorldEven as the Web has become more entertaining--and certainly better looking--over the past 15 years, it has also become much more useful and practical, as the 100 sites in this feature will demonstrate. I've organized the sites in the list by the type of task they help you with. It is not a ranking; in each category I recommend sites that specialize in a different area than the others. I've also mixed in a smattering of sites that you might not use every day, but that provide ready answers to specific questions like "How can I learn to rumba?" or "Who should I vote for?" or "How do I make a wallet out of duct tape?" Most Useful Web Sites by Category 9 Sites to Help You Survive the Recession A growing number of good Web sites, like Prosper and Bankrate, are popping up, offering you cool tools to help you manage and conserve your money. Find and Watch TV and Movies Online Web video is everywhere online these days -- and not just on YouTube. Extras: Complete List by Category (with Links)
Search engine indexingPopular engines focus on the full-text indexing of online, natural language documents. Media types such as video and audio and graphics are also searchable. Meta search engines reuse the indices of other services and do not store a local index, whereas cache-based search engines permanently store the index along with the corpus. Unlike full-text indices, partial-text services restrict the depth indexed to reduce index size. Larger services typically perform indexing at a predetermined time interval due to the required time and processing costs, while agent-based search engines index in real time. Indexing The purpose of storing an index is to optimize speed and performance in finding relevant documents for a search query. Index design factors Major factors in designing a search engine's architecture include: Merge factors Storage techniques How to store the index data, that is, whether information should be data compressed or filtered. Index size Lookup speed Maintenance
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