CSCI-235CSCI-235Micro-Computer in ScienceMicro-Computer in Science

Internet SearchInternet Search

Searching on the WebSearching on the Web

Search Engines- help to find sites related Search Engines- help to find sites related to a specific topic. to a specific topic.

One enters queries or keywords, search One enters queries or keywords, search engine will return many links containing engine will return many links containing those words. Some will rank the relevancy those words. Some will rank the relevancy of the links depending on how many times of the links depending on how many times the words appeared in the pages. the words appeared in the pages.

Search EngineSearch Engine Each Search engine builds its own database of Each Search engine builds its own database of

web pages. web pages. Some engines: Google, Altavista, Yahoo, Bing, Some engines: Google, Altavista, Yahoo, Bing,

Infoseek, Excite Infoseek, Excite Google and Altavista return the links containing Google and Altavista return the links containing

the keywords. It brings back too many irrelevant the keywords. It brings back too many irrelevant hits, it is best used for very specific information. hits, it is best used for very specific information.

Yahoo categorizes data and then let you search Yahoo categorizes data and then let you search when the topic has been narrowed down when the topic has been narrowed down somewhat producing more relevant results.somewhat producing more relevant results.

No search engine is bestNo search engine is best

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Popular Popular WebWeb Search Engines Search Engines

http://www.altavista.com/ http://www.msn.com/

http://www.go.com/ http://www.excite.com/

http://www.lycos.com http://www.askjeeves.com/

http://www.webcrawler.com/ http://www.google.com/

http://www.yahoo.com http://www.search.com/

Search TechniquesSearch Techniques A search engine has its own searching rules. A search engine has its own searching rules. A good guide: A good guide: http://www.windweaver.com/searchguide.htmhttp://www.windweaver.com/searchguide.htm

Some tips:Some tips: Try multiple search engines on one queryTry multiple search engines on one query Use quotes around a string of wordsUse quotes around a string of words Use AND , OR, and NOT to narrow down the topicUse AND , OR, and NOT to narrow down the topic

• And - Includes all findings of both key wordsAnd - Includes all findings of both key words• Or - Looks for only one of the specified key wordsOr - Looks for only one of the specified key words• Not - Allows you to exclude certain key wordsNot - Allows you to exclude certain key words

Use + (-) in front of words to make sure the word is Use + (-) in front of words to make sure the word is included (excluded)included (excluded)