Title: Uusing the world wide web for accessing information
1Uusingthe world wide webforaccessing
information
2- Structure of the Web
- The information available on the World Wide
- Web travels over a computer network called
- the Internet. The Internet consists of
connections - between a vast number of computers around
- the world.
-
- Compared to publishing a book or producing a
television show, creating a Web page is easy and
inexpensive. - Many individuals who cannot reach large audiences
through traditional media, such as books, radio,
or television, can communicate their ideas on the
Web. - In addition to these individually-produced Web
pages, many businesses and organizations are
finding the Web to be an excellent method of
distributing information to the public.
3- Information on the Web
- The Web has no overriding organizational scheme
or structure. Unlike most electronic databases,
there is generally no indexing by topic or
subject. - Although most information on the Web is "free"
(i.e., it can be accessed without restrictions,
passwords, fees, etc), some resources on the Web
require subscriptions. For example, some
newspapers only allow free access to selected
articles and require registration and payment for
the entire issue. - Also, remember that information on the Web is not
screened or edited. Since anyone can publish a
Web page, the type and quality of material tends
to vary!
4- Types of Web Sites
- There are many different types of Web sites.
- Some Web pages provide
- information or news
- attempt to influence public opinion
- sell products
- Entertainment
- Personal outlets
-
- Many Web pages may blur the line between
entertainment, information, and
marketing/advertising. - Web domains
-
- The following are several broad categories or
domains of Web sites which can be distinguished
by the letters at the end of the Web address. (A
Web address is also known as a Uniform Resource
Locator or URL). These letters are a clue as to
what type of Web site you are visiting.
5DOMAIN SAMPLE ADDRESS SAMPLE WEB SITE
.edu educational institution http//www.ucsb.edu
.gov government site http//www.senate.gov
.org non-profit organization or association http//.www.ncaa.org
.mil United States Military or Armed Forces http//.www.af.mil
.com business commercially-based site http//www.cocacola.com The World of Coca-Cola
6Fee-Based or Subscription Web Sites Not all information on the Web is available for free, some sites are restricted to paid subscribers. University/Organization subscriptions Often, universities and other organizations, such as law firms and businesses, subscribe to specialized databases on the Web. These databases can only be accessed by members of a selected community. For example, most of the electronic databases provided by the J. Paul Leonard Library at San Francisco State are only available to the campus community. Access to UofD subscription services are available at on-campus computers. Individual/Personal subscriptions Subscriptions to fee-based Web resources, such as the Inter-Am database, are also available to individuals. Some newspapers and magazines provide the full-text of their issues on the Web to subscribers who are willing to pay. The Wall Street Journal, for example, has a web version that is available by subscription. Commercial services, providing customized information to individuals, are also available, for a fee. An example of one such service is Hoover's company profiles.
7Search Engines
Search engines are used to search for resources on the Internet. When selecting a search engine, be aware that each search engine varies by the amount of the Internet being searched the type of sources being retrieved
There is no search engine that will search the
entire Internet at once. The most popular Web
search engines may only cover up to 25 of all
the content that is available. Often, information
about coverage can be found in a search engine's
Help or About Us sections.
There are many search engines available on the
Web. Here is a sample list Alta Vista / Excite
/ HotBot / InfoSeek / Lycos Magellan /
WebCrawler / Google / Northern Light Search
Engine Tips Always look for the HELP button on
the search engine you select. Useful search
features and options may be explained there.
8Feature Symbol Example Action
Include a keyword intellectual property patents Finds Web sites where the term after the appears in the results.
Exclude a keyword - intellectual property -patents Finds Web sites with intellectual and property, but not patents.
Search for a phrase " " "four score and seven years ago " Finds Web sites which contain the exact phrase.
Search within the title of a Web site title titlemortgage Finds Web sites with mortgage in the title tag.
Search within a site domain site cherry sitewww.pepsi.com Searches within the site www.pepsi.com for the keyword cherry
Search using truncation finan planning Finds Web sites with finance, finances, financial, etc.
Use Boolean operator AND AND montana AND camping Finds Web sites with both terms.
Use Boolean operator OR OR montana OR camping Finds Web sites with either term.
Use Boolean operator NOT NOT montana NOT camping Finds Web sites with montana, but not camping.
Search using nesting ( ) (college OR university) "bookstore" Finds Web sites with college OR university, and bookstore.
9- Subject Directories
- Subject directories are lists of Web sites
arranged by topic or broad subject area. They are
great starting points and are useful for general
topic browsing. - For example, Google and Yahoo offer Web
directories with a comprehensive compilation of
subject categories.
10Metasearch Tools Metasearch tools use several
search engines at the same time to search the
Web. This can be a time saver when doing
extensive searches where you require the broadest
coverage. A few sample metasearch tools are
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http//www.hkta.org/search.html
Hong Kong Tourist Association ONLINE SEARCH
You can use this form to search the pages of Hong
Kong Tourist Association World Wide Web site.
This facility requires a forms-capable browser.
Enter the word or words you want to search for.
Separate multiple words with spaces. Case..
annotation
ranking date domain
- Interpreting Web Search Engine Results
- Look to see if the following information is
available - annotation - most search engines provide
"annotations" with search results. An annotation
is usually an explanation but these annotations
usually just show the first few sentences of the
Web page. They often, however, provide a good
indication about the content of the site. - ranking- some search engines rank results by
various criteria such as relevance, comparing the
information in the site against the information
in the search query. - date- the results from search engines provide a
date which may be useful for evaluating the
currency of a Web site. Be aware that the date
could refer to when the page was created or
updated. - domain- most search engines provide the URL of
the retrieved sites. Check the domain of the URL
to determine whether the Web page is hosted on an
educational site (.edu), a government site
(.gov), an association/organization (.org) or a
commercial site (.com)
Once you have linked to a retrieved site, check
to see if any information is provided about the
producer/creator of the Web page. Often this type
of information is available through links such
as, about this page, about us, about this site,
or a link to the site's home page.
12Evaluating Information from the World Wide Web
Anyone can publish anything on the Web. The
information you find on the web may not be
screened or checked for accuracy! It is up to you
to evaluate the quality of the material you find
on the Web.
The following questions can help you judge the
quality of a particular Web site Accuracy
How reliable and error free is the information?
What kind of documentation or references are
provided? Authority Is the author or source
identified? What kind of qualifications does
the author have? Is a credible sponsoring
institution cited? Is there a link back to the
sponsoring institution's home page?
Objectivity Is the site designed to inform,
persuade, or sell? Is personal bias apparent?
Currency How recently was the site created or
updated? (This kind of information can be
located by checking the header, body, and footer
of a Web document.)
13Summary
- This presentation covered the following
objectives - understanding what the World Wide Web is and how
it is structured - understanding how the Web is organized (or not
organized) - knowing what types of information can be found on
the Web - being able to identify the major types of Web
sites - understanding the difference between "free" and
"fee" Web sites - understanding and being able to use a variety of
Web searching tools - being able to evaluate and interpret Web search
results