Searching the World Wide Web

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Searching the World Wide Web
And Why You Cant Find Everything There
Arlington Campus Library George Mason University
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Our Goals

• Directories, portals, and search engines
• How do the engines work?
• Getting the most from your searches
• Invisible Web
• Authoritative Information

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Three Methods of Searching

• Directories
• Portal
• Search Engine

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Directories

• Directories are organized indexes that allow you
  to browse through lists of Web sites by subject
  or topic.
• Directories are created by people.

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Directories

• Excellent for browsing
• Like visiting a library
• Clearly defined subjects

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Who Creates Directories?

• Libraries
• Nonprofit organizations
• Universities
• Dot-Com businesses
• but they are probably portals too

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A Sampling of Directories

• Librarians Index to the Internet www.lii.org/
• Open Directory Project www.dmoz.org
• Looksmart www.looksmart.com
• Yahoo www.yahoo.com

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Portals

• Portals offer a one-stop shopping look.
• Portals include e-mail, chat, auctions, news,
  weather, horoscopes, stock info, and more.
• Portals want to be YOUR starting point.

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A Sampling of Popular Portals

• Yahoo! www.yahoo.com
• Portals to the World from the Library of
  Congress www.loc.gov/rr/international/portals.htm
  l
• AltaVista www.altavista.com

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Search Engines

• Crawler-based Search Engines
• Spiders aka Crawlers visit websites and some
  of their pages periodically, and adds to index
• Scans links and adds them to their index
• Returns the information to the index or catalog
• Search engine software sifts the index and ranks
  in relevant order
• Some are Focused Crawlers

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Search Engine Watch http//searchenginewatch.com
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Other Search Engine Types

• News Search Engines
• Multimedia Search Engines
• Metacrawlers
• Kids Search Engines
• Regional Search Engines
• See http//searchenginewatch.com/links/

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Power Searching

• Command charts for major search engines at
  http//searchenginewatch.com/facts/ataglance.html
  
• Use Advanced Search at the search engine home
  page to zero in on relevant sites

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www.google.com
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www.google.com
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Understand Limitations of Search Engines

• Search spiders or crawlers do not crawl in
  real time
• Lag times getting info to the index vary by
  search engine
• If a website is not submitted to the search
  engine it wont be crawled
• Not every page from a website is crawled
• A webmaster can choose to not have a page crawled
• Formats like PDF, Flash, Zip files, executable
  programs, and others cannot be searched
• The Invisible Web

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Start Your Search Engines Here

• Google www.google.com
• AllTheWeb www.alltheweb.com
• Yahoo www.yahoo.com
• MSN http//search.msn.com
• Why? See http//searchenginewatch.com/links/majo
  r.html

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Other Resources for Search Engine Info

• Search Engine Showdown Search Engine Features
  http//www.notess.com/search/features/byfeature.sh
  tml
• Search Engine Watch Search Engine Features for
  Searchers http//www.searchenginewatch.com/facts/a
  taglance.html
• How to Choose a Search Engine or Directory
  http//library.albany.edu/internet.choose.html

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Directories Vs Search Engines

• When should you use a directory?
• When you have a broad topic
• When you want experts to recommend sites
• When you want to avoid irrelevant sites
• Examples topics
• Disabilities
• Civil War
• Welfare

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Directories Vs Search Engines

• When should you use a search engine?
• When you have a narrow topic
• When you are looking for a specific website
• When you want to search for a file type or
  language
• Examples
• Americans with Disabilities Act
• Battle of Gettsyburg
• Welfare to Work

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The Invisible Web 4 Types

• Opaque search engines choose not to index
• The Private Web password protected
• The Proprietary Web registration required
  (either fee or free)
• The Truly Invisible Web cant search certain
  file formats and databases

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Examples of Invisible Web Sites

• Dictionaries http//www.m-w.com
• Telephone Numbers http//www.infospace.com
• Clinical Trials http//www.clinicaltrials.gov
• Library Catalogs http//www.libdex.com/webcats
• Philanthropy and Grant Information
  http//lnp.fdncenter.org/finder
• Translation Tools http//world.altavista.com

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More Information on the Invisible Web

• The Invisible Web Uncovering Information Sources
  Search Engines Cant See, by Chris Sherman and
  Gary Price, ZA 4550 .S54 2001
• http//www.invisible-web.net/ website that goes
  with the book. Includes a subject directory of
  invisible web sites.

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Evaluating Online Information

• Always judge a web page for relevance and
  accuracy
• Who is the Author?
• What is the Purpose of the site?
• Is the information Fact, Opinion, or Propaganda?
• Is the information Reliable and Credible?
• Is the information Current?

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Evaluating Web Sites Continued

• Can you find this news reported on a legitimate
  news website?
• Who is the sponsor of the website?
• Are there inconsistencies or inaccuracies in the
  information?
• If an organization is mentioned by name, does the
  organization have any related information on this
  website?

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Thank You.!!! ?

• You can find this PowerPoint presentation on the
  Arlington Campus Library Website at
  http//library.gmu.edu/libinfo/acl.html under
  Useful Sites - bottom right of screen.