Searching

1
Searching
Search results are only as good as the query you
pose and how you search. There is no silver
bullet
2
Some of the Major Internet Sites for Searching
(There are more than 2500)

• Altavista
• Ask Jeeves
• Google
• Infoseek
• Northernlight
• Excite
• Hot Bot
• Go

• About
• Magellan
• NetFind(AOL)
• Lycos
• Inktomi
• Looksmart
• Dogpile(Metasearch)
• Metacrawler(Metasearch)
• Mama (Metasearch)
• Savycrawler(Metasearch)

3
Facts

• 1 Billion or more Internet Documents
• Combining multiple search engines in a given
  search can increase the likelihood of finding the
  information desired by a factor of 3.5 or more
• 50 of searches find broken links
• Catalog Altavista (47)

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Searching

• Search Engines (searching a database)
• Index words or terms found in Internet Documents
• Spiders or crawlers programs
• Index (database)
• Title, metatags, Expanding references, Do other
  pages link to the page
• Factors (size of database, frequency of updates,
  search capabilities)
• In general best for a specific piece of
  information rather than general information)
• Google, Excite, Altavista
• Meta Search Tools (Dogpile and Metacrawler)
• Subject specific search engines that aim for
  depth rather than coverage of WWW
  (www.beacoup.com), www.searchengines.com

5
Searching

• Directories
• Classify web documents into categories and then
  use a search engine to search their categories
• Yahoo.com
• They require people to view the individual Web
  site and determine its placement into a subject
  classification scheme. Once done, certain
  keywords associated with those sites can be used
  for searching the directory's data banks to find
  Web sites of interest.
• Databases tend to be smaller than Search Engines

6
Google

• 100 million searches every day
• 97 of users find what they need most of the time
• 15 million visitors each month
• Contains its own system of measuring relevancy,
  partially based on number of links to that site
• Indexes more than 4 billion Web Pages, Index
  stored on 10,000 PCs
• Considers Microsoft and Yahoo its main
  competitiors
• 40 computer science PhDs maintain it
• Employs 2,292 people

7
Evaluating Information

• Accuracy and Authority
• Is there an author? Who wrote the page can you
  contact them
• Is the person qualified who wrote the page
• Why was the document produced
• Is their an e-mail address provided for questions
• Is their an author or is it a Webmaster
• What Institution is hosting the site dissect
  the URL
• (look at the domain name)

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Evaluating Information

• Objectivity
• What are the goals of the page
• Inform, advertise or convince
• How detailed in the information
• Opinions or facts
• Currency
• When was it produced
• Are there dead links
• When was it updated

• Coverage
• How in-depth is the material
• Do links lead to relevant information
• Can you find the same information elsewhere

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Types of Web Pages

• Advocacy Web Page
• Democratic Party
• Society for the Prevention of Cruelty to Animals
  
• Business/Marketing
• IBM, DELL, Walt Disney
• Informational Web Page
• Government Agencies
• Public Transportation
• News Web Page
• Portal Web Page
• Personal Web Page

• News Web Page
• Magazine
• Newspapers
• TV
• Portal
• Altavista, Lycos, MSN, AOL
• Personal
• Laurie Shteir

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Search Tips

• Natural Language
• Boolean Algebra (AND,OR,NOT)
• Mozart OR Beethoven
• Symbols , , -_
• Cherokee jeep
• quotation marks for phrases great barrier reef
  python-monty
• HotelsParis-Bed and Breakfast