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Uusing the world wide web for accessing information.

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Presentation on theme: "Uusing the world wide web for accessing information."— Presentation transcript:

1 Uusing the world wide web for accessing 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.

5 DOMAINSAMPLE ADDRESSSAMPLE WEB SITE.edu = educational institution http://www.ucsb.edu.gov = government sitehttp://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

6 Fee-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.

7 Search 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.

8 FeatureSymbolExampleAction 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:title:mortgage Finds Web sites with mortgage in the title tag. Search within a site domain site: cherry site:www.pepsi.c om 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 ORmontana OR campingFinds 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.

10 Metasearch 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:

11 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.. 99%1998/04/08http://www.hkta. org /search.html ann o t a t i o n rankingranking datedate do m a i n 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.

12 Evaluating 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.)

13 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 Summary


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