Search Engines The Information Retrieval Tool By Vinodkumar

Search Engines: The Information Retrieval Tool By VINODKUMAR Librarian Govt. First Grade College KAMALAPUR - 585 313 Gulbarga (Dist.) www.freewebs.com/vinodchapter / July 13, 2009

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Overview 

Internet

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Search Engines Crawler Based Search Engines

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Human Powered Directories

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Hybrid Search Engines

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Meta Search Engines

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Web Search Strategies Boolean Operators

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Major Search Engines on the web

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Conclusion

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Internet • • •

Internet is known as network of networks. Facilitates communication both nationally and internationally, Enables computers around the world to share services and resources,

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Web Search Engine • Definition: – huge databases of web page files that have been assembled automatically by machine.

• Type: – Individual: compile its own databases – Meta: search the DB of other individual engines

• Examples: FastSearch, AltaVista, Google Ixquick, Metor, Vivisimo

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Web Search Engine “The Web is a vast collection of completely uncontrolled heterogeneous documents”. • "spiders" or "robots" ("bots") are used to crawl through Internet, identifying and perusing pages to compile their databases. • Most of the words on the publicly available pages are indexed. • Web pager owners can submit their URL to search engines. Not all web pages are crawled. July 13, 2009

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Web Search Engine • Retrieve relevant information with less effort and time • Similar to Library catalogues • Indexes the list of web pages • Facilitates various search options

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Types of Search Engines

 Crawler-based search engines,  Human-powered directories,and  Hybrid Search Engines.

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Search Planning • Identify your concepts • Make a list of search terms for each concept • Specify the logical relationships among your search terms

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Web Search Strategies • Boolean Logic operator – Boolean logic consists of three logical operators: – OR – AND – NOT

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OR logic Operator Eg:- rain OR snow

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AND logic Operators • All the terms joined by "AND" must appear in the pages or documents. Some search engines substitute the operator "+" for the word AND. • Ex: - poverty AND crime

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AND logic Operators poverty AND crime

poverty AND crime AND gender

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NOT logic operator • This Boolean operator is used in order to require that a particular search term should not be present on web pages listed in results, which will exclude search. Some search engines substitute this operator "-" . • Ex: - rain NOT snow rain - snow July 13, 2009

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Nesting ()       • Nesting allows building complex queries. Nesting refers to use of parentheses for building complex queries. For instance the query – Ex:-Management AND (Fayol OR Taylor) July 13, 2009

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Phrase Search      • The words between the quotation marks are treated as a phrase, and that phrase must be found within the document or file, as exactly as it appears. Eg:- “freedom of the press” July 13, 2009

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Title field search A title search can bring you more relevant results than merely searching for words without any limitation. It's more likely that a document that contains your search words in the title will be more relevant that a document that does not. For this reason, many search engines use title words as an important way of ranking search results in order of their relevancy.

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Title field search allintitle: hurricane caribbean deaths

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Site field search Searching on the site field is another useful way of finding relevant results. In this case, you search on the top-level and second-level domain names together, and then use AND logic to add topical words to your search. Examples of sites: www.nasa.gov www.mit.edu www.microsoft.com

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Site field search spacewalks site:nasa.gov.

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Google Advanced Search

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Search Engines  Alltheweb (Fast Search) [http://www.alltheweb.com]  Altavista [http://www.altavista.com]  Askjeeves [http://www.askjeeves.com]  Google [http://www.google.com]  Yahoo [http://www.yahoo.com] July 13, 2009 orien_UGC-ASC-BUB

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SEARCH TOOLS METASEARCH TOOLS SUBJECT DIRECTOR Google Advanced Search INFOMINE Yahoo! Advanced Search Ixquick Academic Info Metasearch Ask Advanced Search  Best Information on the Net VivísimoSurfwax All the Web  Internet Public Library ProFusion Advanced Search Librarians' Index to the Inter Dogpile  MSN Search  The Scout Report Archives Advanced Search Clusty  Direct Search Exalead Advanced Search Mamma Digital Librarian Teoma Advanced Search Ithaki About.com Alta Vista  KillerInfo  World Wide Web Virtual Lib Advanced Search Beaucoup Gigablast  Complete Planet:The Deep W Kartoo Advanced Search Search.com Open Directory Project  Lycos Advanced Search  HotBot Advanced Search A9.com July 13, 2009

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AltaVista – Site Submission

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AltaVista

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Conclusion • Information is growing exponentially. • Rapidly growing Internet-based content. • Identifying relevant resources is a major problem. • Uncertainty about the quality. • Searching information on the Internet is a complex process. • Poor quality searches – information overload. • Organizing skill is required.

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Thank you July 13, 2009

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