Search Engines
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Supichaya Nuntapunt

Supichaya Nuntapunt
Search Engines
for Mae Fah Luang University
Freshmen 2010 Live & Learn

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  • Go through these procedures fairly quickly: there’s an exercise to learn this You want them to be able to understand the form and what it says. DOMAIN APPROPRIATE FOR THE CONTENT: Do you trust a NYT times article from a personal page as much as one from nytimes.com? A copy of Jackie Onassis’s will from a personal page as much as one from the California Bar Assn.? Example of a personal page would be: www.aol.com/~jbarker They are loosely paralleled by the sequence of the form in the next exercise.
  • You can trust the lii.org more than many referrals. If there are annotations by professionals, that helps. The burden is on you, always. Demonstrate link: search example in Google. Use http://www.hanksville.org/yucatan/mayacal.html

Search Engines Search Engines Presentation Transcript

  • SEARCH ENGINE Live and Learn 2010 Aj. Supichaya Nuntapunt School of Information Technology Mae Fah Luang University
  • The Web Defined
    • Software application that allows us to publish and browse hypertext documents
    • Transported over Internet
    • HTTP
    • Browsers are multiprotocol
    • URL = Web address
  • Introduction
    • Directories, Search Engines, and Metasearch Engines
    • Search Fundamentals
    • Search Strategies
    • How Does a Search Engine Work?
  • Directories, Search Engines, and Metasearch Engines
    • Directories
    • Popular Directories
    • Search Engines
    • Popular Search Engines
    • Metasearch Engines
    • Popular Metasearch Engines
  •  
  • Directories
    • Hierarchical representation of hyperlinks
    • Top level of general topics
    • Sublevels of more specialized subtopics
    • Easy to use
    • Not necessary to know exactly what looking for
  • Popular Directories
    • AOL NetFind
    • CNET Search.com
    • Excite
    • Infoseek
    • Looksmart
    • Lycos
    • Yahoo!
    • Open Directory (dmoz.com)
  • Search Engines
    • Computer program:
      • Accepts a query
      • Searches database
      • Returns URLs
      • Permits query revision
    • Problem: many times search engine return too many URLs. You need to be specific!
    • Query syntax
  • Popular Search Engines
    • Google (85.35%), Yahoo(6.29%), Bing (3.27%)
    • AOL, Ask, AltaVista, Excite, HotBot, Lycos, Fast search (alltheweb.com), DogPile
    • As of December 2009
    Ross Shannon: HTML Source http://www.yourhtmlsource.com
  • HitWise http://www.hitwise.com/us/datacenter/main/dashboard-10133.html
  • Ranks.nl - Compare Search Engines http://www.ranks.nl/tools/compare.html
  • Metasearch Engines
    • Call other search engines
    • Use single query
    • More matches
  • Popular Metasearch Engines
    • Metasearch
    • Metacrawler
  • Search Fundamentals
    • Search Terminology
    • Pattern Matching Queries
    • Boolean Queries
    • Search Domain
    • Search Subjects
  • Search Terminology
    • Search tool
    • Query
    • Query syntax
    • Query semantics
    • Hit or Match
    • Relevancy score
  • Pattern Matching Queries
    • Enter keyword(s)
    • Search engine returns URLs
  • In-line/On-line: Fundamentals of the Internet and the World Wide Web
  • Boolean Queries
    • George Boole
    • AND, OR, and NOT
    • Examples:
      • You want to search for bass (the fish not the musical term)
      • Vacation in either London or Paris
  • Search Domain
    • Web
    • Newsgroups
    • Specialized databases
    • Library
  • Search Subjects
    • Metaspy shows searches for metacrawler in realtime.
    • Google Search History
  • Introduction – Choose a search engine
    • User-friendly interface
    • Documentation
    • Database size
    • Relevancy scores
  • Too Many Hits: Search Specialization
    • Add keywords
    • Add AND or NOT
    • Capitalize proper nouns
    • Use first 20 URLs
  • Too Few Hits: Search Generalization
    • Eliminate keywords
    • Remove AND or NOT
    • Enlarge search domain
    • General keywords
  •  
  • How Google works
    • BEFORE you search: “Crawls” pages on the public web Copies text & images, builds database
    • WHEN you search: Automatically ranks pages in your results
      • Word occurrence and location on page
      • Popularity - a link to a page is a vote for it
      • ~ 200 factors in all!
  • Searching Google
    • Think “full text” = be specific
      • war of 1812 economic causes vs. history
    • Use academic & professional terms
      • domestic architecture vs. houses genome society gets International Mammalian Genome Society also try combinations with association , research center , institute , directory , database
  • Searching Google
    • Specify exact phrases
    • “ tom bates” “what you're looking for is already inside you”
    • Exclude or require a word
      • proliferation -nuclear
      • bush legacy +environment
  • Limit your search to …
    • Web page title intitle:hybrid allintitle:hybrid mileage
    • Website or domain site:whitehouse.gov “global warming” site:edu “global warming”
    • File type filetype:ppt site:edu “global warming”
  • On the results page
    • Search box (use to modify)
    • “ Cache”
    • “ Related pages”
    • “ Translate this page”
  • Let’s try it !
    • Search Google
    • Use our examples or your own topics
    www.google.com
  • Google’s other databases
  • Why go beyond Google?
    • Search more of the web Yahoo!
    • Get more options Exalead
  • Let’s try it !
    • Try other search tools
    • Compare results with Google
  • CRITICAL EVALUATION Why Evaluate What You Find on the Web?
    • Anyone can put up a web page
    • Many pages not updated
    • No quality control
      • most sites not “peer-reviewed”
        • less trustworthy than scholarly publications
  • Before you click to view the page...
    • Look at the URL - personal page or site ? ~ or % or users or members
    • Domain name appropriate for the content ?
      • Restricted: edu, gov, mil, a few country codes (ca)
      • Unrestricted: com, org, net, most country codes (us, uk)
    • Published by an entity that makes sense ?
      • News from its source?
        • www. nytimes .com
      • Advice from valid agency?
        • www. mfu .ac.th
        • e-learning . mfu .ac.th
  • Scan the perimeter of the page
    • Can you tell who wrote it ?
      • name of page author
      • organization, institution, agency you recognize
    • Credentials for the subject matter ?
      • Look for links to:
      • “ About us” “Philosophy” “Background” “Biography”
    • Is it current enough ?
      • Look for “last updated” date
  • Examine the content
    • Text
        • possibly forged ?
    • Sources
        • documented with links or notes ?
        • do the links work ?
    • Evidence of bias
        • in text or sources ?
  • Do some detective work
    • Search the URL in alexa.com
      • Click on “Site info for … ”
      • Who owns the domain?
      • Who links to the site?
      • What did the site look like in the past?
      • www.archive.org/web/web.php
      • (Wayback Machine)
  • Does it all add up ?
    • Was the page put on the web to
      • inform ?
      • persuade ?
      • sell ?
      • as a parody or satire ?
    • Is it appropriate for your purpose?
  • Try evaluating some sites...
    • Search a topic in Google
    • Scan the first two pages of results
    • Visit one or two sites
      • evaluate their quality and reliability
  • Questions?
  • References
      • John Kupersmith: University of California, Berkeley
      • Greenlaw/Hepp, In-line/On-line: Fundamentals of the Internet and the World Wide Web
    THANK YOU