Transcript The Internet Web Basics

The Internet
Web Basics
Dr. Dania Bilal
IS 587
Fall 2007
The Internet
• Beginning
– Internet without content
– Used for email and FTP
– Internet with content
• Usenet newsgroups
• Directory: Gopher
Gopher
• Menu-driven content
• Used by universities
• Gopher was indexed by
– Jughead
– Veronica
WWW
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1991, Tim-Berners Lee created WWW
GUI interface
Hypertext navigation of content
Multimedia (text, sound, graphics)
1995, Web has become popular and
search engines were developed
Web
• Web interfaces took over text-based
interfaces such as ftp
• Search engines spread
• Web directories
• Search engines have become portals
– Multi-functions
Internet History
• See Timeline in Text, chap. 1
• See URLs for Internet history and growth,
chap. 1
– http://www.extremesearcher.com/handbooklin
ks.html#chap1
Searching the Web
• General search engines
• Specialized search engines
• Engines vs. portals
• Meta-search engines
• Directories
• Meta-directories
All is found at
http://searchenginewatch.com/showPage.html?p
age=2156221
Use of Engines & Directories
• Engines
– To search by keyword, phrase, etc.
– Topic is specific
– Complex searches
• Lots of information is retrieved
• Searching is done in billions of pages
• Directories
– To browse by categories
• From broad to specific
– Simple searches
• Less information is retrieved
• Searching is done in millions of pages
Basic Search Strategy
• Identify information need
• Extract basic concepts
• Formulate strategy using concepts and
appropriate search parameters
– Boolean, proximity, search limiting, as
appropriate
• Select appropriate engine, directory, metaengine, or meta-directory
Basic Search Strategy
• Conduct the search (pay attention to
spelling)
• Examine first page of results for relevance
• Revise search based on results retrieved
• If not satisfied, use another search
engines or directory
Note: Meta-engines and meta-directories are used when
lots of information is needed for research purposes.
The Question of Quality
• Criteria for evaluating information quality
– Source domain (.com, .edu, .gov, etc.)
– Authority
– Purpose or motivation
– Quality of writing
– Balanced views
– Currency of information
– Sources cited
The Question of Quality
• Accuracy
• Factual information (check against two or
more authoritative sources)
– Currency
http://www.virtualchase.com/quality
http://www.lib.berkeley.edu/TeachingLib/Guides/Int
ernet/Evaluate.html
http://epress.lib.uh.edu/pr/v8/n3/smit8n3.html
(content quality and design/navigation)
The Invisible Web
• Search engines don’t index all web pages
• Reasons:
– Page are password-protected
– Pages are too deep (too much to index)
– Pages not picked up by spiders or crawlers
• See sites for finding information on the IW
in Text.
Overview of Web 2.0
• Web 2.0: The machine is us/ing usvideo
found at http://www.youtube.com
– Search under
• Web 2.0 (video)
• What is web 2.0 (video)
• http://en.wikipedia.org/wiki/Web_2
– Definition, characteristics of Web 2.0, and
other information