World Wide Web

1
World Wide Web

• History of the Internet and WWW
• Structure
• Searching the Web
• Evaluating Information

2
HistoryTimeline

• 1969 Internet begins as ARPANET, an
  experimental 4-computer network, was established
  by the Advanced Research Projects Agency (ARPA)
  of the U.S. Defense Dept.
• 1971 ARPANET linked about 2 dozen computers
  ("hosts") at 15 sites, including MIT and Harvard
  (By 1981, there were over 200 hosts)
• 1978 first spam, or junk e-mail, message sent
  over ARPANET
• 1980s more and more computers using different
  operating systems connected
• 1983 the military portion of ARPANET moved
  onto the MILNET
• 1985 America Online (AOL), commercial internet
  service provider, premieres

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HistoryTimeline, contd

• Late 1980s the National Science Foundation's
  NSFNET began its own network and allowed public
  access to it
•  1988 Internet Relay Chat (IRC) was developed
  by Finnish student Jarkko Oikarinen, enabling
  people to communicate via the Internet in "real
  time
• 1989-90 World Wide Web invented by Tim
  Berners-Lee as an environment in which scientists
  at CERN (European Center for Nuclear Research)
  could share information. It gradually evolved
  into the medium we know now.
• Tim Berners-Lee named his precursor of the World
  Wide Web, ENQUIRE, after the work Enquire Within
  Upon Everything, a late 19th century how-to book
  for domestic life. (Check it out! rather
  amusing.)

4
HistoryTimeline, contd

• 1991 commercial traffic admitted to the
  NSFNET release of the first browser, or software
  for accessing the World Wide Web
• 1993 Mosaic, the first graphical Web browser
  -- the first Web browser with mass appeal is
  developed for Microsoft Windows, Unix systems
  running the X Window GUI, and the Apple Macintosh
• 1994 Netscape Communications releases Netscape
  Navigator browser
• 1994 Yahoo, a subject directory for the Web,
  was developed
• 1995 Microsofts Internet Explorer browser was
  released, but initially fails to make a dent in
  Netscape's dominance of the browser market
• 1995 Amazon.com opened in Seattle

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HistoryTimeline, contd

• 1996 Browser wars heat up as Microsoft Corp.
  releases Internet Explorer 3.0 and Netscape
  releases Navigator 3.0
• 1996 Internet2 was launched
• 1997 AOL acquired CompuServe
• 1998 Netscape's market share fell below 50,
  while Internet Explorer's exceeded 25.
• 1998 Google.com premiered
• 2000 Hackers took down major Web sites with
  massive distribution of denial-of-service attacks

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The Future?

• Grid computing
• computing as a utility, like electricity tap
  into a network for computing power
• massive integration of computer systems to offer
  performance unattainable by any single machine.
• users will begin to experience the Internet
  as a seamless computational universe. Software
  applications, databases, sensors, video and audio
  streams all will be reborn as services that live
  in cyberspace, assembling and reassembling
  themselves on the fly tomeet the tasks at hand.
  Once plugged into the grid, a desktop machine
  will draw computational horsepower from all the
  other computers on the grid. Is Internet history
  about to repeat itself? (2002). Technology
  Review, 105 (4), 32-36.

7
Definitions
Browser A program that accesses the WWW and
reads hypertext CGI Common Gateway Interface
a programming mechanism for servers Domain The
naming hierarchy of the Internet is based on
domains (e.g. aUniversity department), within
which each computer has a unique name domain
name server (DNS) DNS converts a machine name
(e.g.Journals_at_elsevier.co.uk) to a numerical IP
Internet address ftp File Transfer Protocol a
mechanism for transferring files across anetwork
HTML HyperText Markup Language the coding
syntax used to write WWW pages, which are read by
browsers
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Definitions, contd
HTTP Hypertext Transfer Protocol the WWW
protocol that performs therequest and retrieve
functions of a server Hypertext The basic
concept behind the WWW, where one resource can be
linked to any other information elsewhere found
on the WWW Internet The worldwide distributed
network of computers connected using TCP/IP, or
similar protocols IP number The unique number
for a machine on the Internet (see domain name
server) Protocol A means by which different
types of computers communicate with each other
(see TCP/IP)
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Definitions, contd

• Server A computer, or a program on the computer,
  acting as an Internetsite providing data
  available to the client service provider, or
  Internet Service Provider (ISP) A commercial
  company that sells Internet connection facilities
  
• TCP/I Transmission Control Protocol/Internet
  Protocol thecommunications program common to
  most connected Internet computers
• URL Uniform Resource Locator an address that
  specifies the location ofa file on the Internet
  (e.g. http//www.elsevier.com/locate/trendsguide),
  usually used for the WWW
• What can the URL tell you about a WWW site?

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Types of Web Resources

• Commercial amazon.com
• Government State of Oregon
• Educational University of Oregon
• Personal/Group Ted D. Smith, CET News
• Association American Psychological Association,
  Modern Language Association

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What the URL can tell you
Domains .gov Government agency
www.whitehouse.gov .net Internet Service
Provider www.whitehouse.net .com Commercial
site (Note www.whitehouse.com is a pornographic
site. You must be over 18 to view.) .edu Higher
education www.lesley.edu. Other educational
sites may appear with different domain names
www.whitehouse.gov/kids .mil Military site
www.navy.mil/ ("tilde") Personal site
http//www.members.tripod.com/DAdams/qkbrdinf.htm
l .org Organization may be charitable,
religious, or a lobbying group
http//www.rtda.org. See Domain Suffix Listings
for more
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• What are these?
• (Exercise)
• http//caltechlib.library.caltech.edu/71/01/OABest
  iary.pdf
• http//home.earthlink.net/markdlew/shw/ixnarr.htm
  
• http//www.recmusic.org/lieder/
• http//www-ed.fnal.gov/projects/scientists/index1.
  html
• http//www.chemie.fu-berlin.de/chemistry/general/c
  onstants.html

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• http//www.springerlink.com/(bbbvql45wzay1g45nzmu4
  5rk)/app/home/issue.asp?referrerparentbacktojou
  rnal,2,13browsepublicationsresults,72,2516
• http//www.dhmo.org/
• http//www.cam.ac.uk/
• http//www-lexikon.nada.kth.se/skolverket/sve-eng.
  shtml
• http//www.gummers.co.uk/
• http//www.bensonhs.pps.k12.or.us/
• www.ci.eugene.or.us/

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Searching the WWW
What's a Google? "Googol" is the mathematical
term for a 1 followed by 100 zeros. The term was
coined by Milton Sirotta, nephew of American
mathematician Edward Kasner, and was popularized
in the book, "Mathematics and the Imagination" by
Kasner and James Newman. Google's play on the
term reflects the company's mission to organize
the immense amount of information available on
the web. From Google Corporate
information http//www.google.com/corporate/index
Google The Movie
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Advanced Google Searching

• Boolean logic is operating in Googles searches.
• By specifying whether you want your terms
  combined with ORs, ANDs, or NOTs, or
  searched as a PHRASE, you can increase the
  relevance of your results.
• You can use the Google Advanced Search mode, or
  you can type in the specific symbols Google uses
  yourself
• or OR (must be capitalized)
• and (plus sign)
• not - (minus sign)
• phrase (enclose the words in quotation
  marks)

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Advanced Google Searching, contd

• You can also limit to certain types of sites
  (such as higher education), by limiting to that
  domain suffix
• type site, e.g. site .edu
• See Google Searching Guide for more information
• Other limits are also available on the Google
  Advanced Search page (currency, file formats, in
  what part of the html document your terms
  appear).

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Other Search Engines

• Federated or meta-search engines, e.g. Vivisimo,
  Dogpile
• These search engines search across other search
  engines (such as Google, Yahoo, etc.) and may
  have helpful features like clustering of search
  results.
• Other standard search engines, which may be
  better for certain types of searching e.g.,
  Altavista has strong international coverage, and
  translation ability for 5 languages.
• Deep Web
• Multimedia
• Scholarly new resource Google Scholar
• See the Librarys Search Engine web page for more

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Evaluating Information

• Criteria
• Authority is it signed? Who is the author?
  Credentials? Sponsor of the web page can you
  tell who that is? Does the sponsor seem to have
  an agenda?
• Accuracy obvious mistakes e.g. bad grammar,
  misspellings unclear or misleading graphics is
  there an editor or someone who verifies/checks
  the information?
• Objectivity is there a purpose to the page
  does it appear to have a minimum of bias or does
  it seem designed to persuade or sway opinion?
• Currency when was the page created (does it
  say?) Has it been revised or updated? Do the
  links work?
• These criteria can also apply to information
  found in other sources.

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Evaluating Information
For more information, see Evaluating
Information on the World Wide Web
(UO) Evaluating Web Sites (Lesley
University) Thinking Critically About World Wide
Web Resources (UCLA)
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When to Search the Web

• The Web is a good place to look for certain types
  of information
• Information likely to be published by or about
  an individual, an association or organization, a
  business, the government
• Very current information about world events,
  news, etc.
• For other types of information, books or journal
  articles will be much better sources.

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When to NOT Search the Web

• Avoid searching for
• Very focused topics, such as a specific event in
  history, a report of the results of some kind of
  study
• Journal articles are the best source for this
  information search a periodical database
• Broad topics, like the history of a country or a
  cultural practice spanning a long period of time
• Books are usually the best source for this
  information search a library catalog