Search engines and web directories
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Transcript of Search engines and web directories
Information Literacy
Karina Joyce E. LimboBLIS-IIIProf. Farquerabao
Search Engines and Web Directories
Search Engine
Programs that search documents for specified keywords and returns a list of the documents where the keywords were found.
Search that enable users to search for documents on the World Wide Web.
3 Important Elements of Search Engines
Discovery and Database A search engine finds information for
its database by accepting listings sent in by authors wanting exposure, or by getting the information from their "Web crawlers," "spiders," or "robots," programs that roam the Internet storing links to and information about each page they visit.
User Search
Most engines allow you to type in a few words, and then search for occurrences of these words in their data base.
Presentation & Ranking
Search engines give each document they find some measure of the quality of the match to your search query, a relevance score.
Examples of Search Engine
Bing Google Yahoo! Windows Live Search
Web Directories
directories where different resources are gathered.
web directory is not a search engine and does not display lists of web pages based on keywords; instead, it lists web sites by category and subcategory.
Difference from Search Engine
most directories are edited by humans.
URLs are not gathered automatically by spiders but submitted by site owners.
Examples of Web Directory
DMOZ
Yahoo! Directory
Evaluating Internet Information
Accuracy-How reliable is the information
provided at the site? Have the facts been checked by someone other than the site's author or creator?
Authority-Is the author or editor of the Web page qualified to write on the stated subject? What are his/her credentials (education, occupation, previous publications)?
Objectivity-If the subject is controversial, is the information presented fairly (both pros and cons) or in a one-sided manner? Examine the content carefully for possible bias.
Currency-Is the information provided at the site up-to-date or out-of-date?
Coverage-What topics (subjects) are covered by the Web site?