Searching the World Wide Web




Дата канвертавання28.04.2016
Памер48.77 Kb.

Searching the World Wide Web


Brought to you by the Purdue University Online Writing Lab at http://owl.english.purdue.edu
Check out our search engine tutorial for an interactive experience that will help you learn about searching the web at http://owl.english.purdue.edu/internet/search/index.html.

Searching the World Wide Web can be both beneficial and frustrating. You may find vast amounts of information, or you may not find the kinds of information you're looking for. Past studies have indicate that search engines index only about 16% of the total content on the Web and that they are biased toward well known information. (One study found that Northern Light has about 16% of the total content and Snap and Alta Vista each have about 15.5%; Lycos has about 2.5%.) Moreover, the content on search engines can be at least several months old, although new indexing techniques are making this less likely.

So, using search engines is not the only way to find material on the web, but they are one tool you can use. Knowing a few search strategies and hints, as you use these engines, can make the search more profitable.

One way to improve your Web searching techniques is to meet with a Writing Lab tutor in the Lab (226 Heavilon, 494-3723), work together on the Web on one of our computers, and get some advice from the tutor. We also have a search engine tutorial at http://owl.english.purdue.edu/internet/search/index.html, and several PowerPoint presentations on searching the web at http://owl.english.purdue.edu/workshops/pp/index.html. In addition, the following suggestions should help.



Kinds of Search Engines || Using a Search Engine || List of Search Engines || Other Strategies For Your Searches


Kinds of Search Engines

1. Catalogues


These are broken down into categories and are good for broad searches of established sites. For example, if you are looking for information on the environment but not sure how to phrase a potential topic on holes in the ozone, you could try browsing through Yahoo's categories. In Yahoo's "Society and Culture" category (at http://www.yahoo.com), there is a subcategory of "environment" that has over subcategories listed under that. One of those subcategories is "ozone depletion," with over twenty references, including a FAQ site. Those references can help you determine the key terms to use for a more focused search.

2. Search engines


These ask for key words and phrases and then search the Web for results. Some search engines look only through page titles and headers. Others look through documents. Many search engines now include some categories as well.

3. Metasearch engines


These (such as Dogpile at http://www.dogpile.com and Metacrawler at http://www.metacrawler.com) search other search engines and often search smaller, less well known search engines and specialized sites.


Using a Search Engine

Learn how the search engine works


Read the instructions and FAQs to learn how that particular site works. Each search engine is slightly different, and a few minutes learning how to use the site properly will save you large amounts of time and prevent useless searching.

Each search engine has different advantages; for example, Alta Vista (at http://www.altavista.com) offers the option of selecting which language you want to search in and HotBot (at http://www.hotbot.com) permits you to specify date, location, media type, etc. for the references it searches for. Infoseek (http://www.infoseek.com) permits you to ask questions.


Select your terms carefully


Using inexact terms or terms that are too general will cause you problems. If your terms are too broad or general, the search engine may not process them. Search engines are programmed with various lists of words the designers determined to be so general that a search would turn up hundreds of thousands of references. Check the search engine to see if it has a list of such stopwords. One stopword, for example, is "computers."

If your early searches turn up too many references, try searching some relevant ones to find more specific or exact terms. You can start combining these specific terms with NOT (see the section on Boolean operators below) when you see which terms come up in references that are not relevant to your topic. In other words, keep refining your search as you learn more about the terms.

You can also try to make your terms more precise by checking the online catalog of a library. For example, check THOR at http://www.lib.purdue.edu, the Purdue University Library online catalog, and try their subject word search. Or try searching the term in the online databases in the library.

If you use AltaVista (at http://www.altavista.com), you'll find their LiveTopics very useful. After you enter your key terms and get the results, you will notice a LiveTopics option on the top of the page that has a list of possible related keywords. You can highlight some and reject others to narrow your search.


Know Boolean operators


Most search engines allow you to combine terms with words (referred to as Boolean operators) such as "and," "or," or "not." Knowing how to use these terms is very important for a successful search.

AND

AND is the most useful and most important term. It tells the search engine to find your first word AND your second word or term.

AND can, however, cause problems, especially when you use it with phrases or two terms that are each broad in themselves or likely to appear together in other contexts.

For example, if you'd like information about the basketball team Chicago Bulls and type in "Chicago AND Bulls," you will get references to Chicago and to bulls. Since Chicago is the center of a large meat packing industry, many of the references will be about this since it is likely that "Chicago" and "bull" will appear in many of the references relating to the meat-packing industry.



OR

OR is not always a helpful term because you may find too many combinations with OR. For example, if you want information on the American economy and you type in "American OR economy," you will get thousands of references to documents containing the word "American" and thousands of unrelated ones with the word "economy."

Use OR when a key term may appear in two different ways. For example, if you want information on sudden infant death syndrome, try "sudden infant death syndrome OR SIDS."

NEAR

NEAR is a term that appears only on some search engines, and it can be very useful. It tells the search engine to find documents with both words but only when they appear near each other, usually within a few words.

For example, suppose you were looking for information on mobile homes, almost every site has a notice to "click here to return to the home page." Since "home" appears on so many sites, the search engine will report references to sites with the word "mobile" and "click here to return to the home page" since both terms appear on the page. Using NEAR would eliminate that problem.

NOT

NOT tells the search engine to find a reference that contains one term but not the other.

Some search engine sites have advanced or power options for searches, and you can read about those to see how they can help you.

Know the limitations of the Web and of search engines


The World Wide Web is a superb resource, but it doesn't contain all the information that you can find in libraries. Don't expect to limit your search to what's on the Internet, and don't expect search engines to find some very recent information or to find everything that is on the Web. After you try several search engines, you will see that you get different results from different sites. Also, remember that some information appears and then disappears from Web sites.

Search engines will put the most relevant sites at the top of their lists, but most engines determine relevancy by the number of key term matches. This means that the most repetitive site will be the most relevant in their list, and that may not turn up the best sites for your use.




Search Engines


Some of the most powerful search engines include the following that you'll find on OWL's Search Tools & Directories on the Net at http://owl.english.purdue.edu/internet/tools/index.html.

  • Alta Vista at http://www.altavista.com/

  • Dogpile at http://www.dogpile.com/ (is a metasearch engine and will search other search engines)

  • Excite at http://www.excite.com/

  • Google at http://www.google.com/

  • HotBot at http://www.hotbot.com/

  • Infoseek at http://www. infoseek.com/

  • Lycos at http://www.lycos.com/

  • Metacrawler at http://www.metacrawler.com/ (is a metasearch engine and will search other search engines)

  • Northern Light at http://www.nisearch.com

  • Open Text at http://index.opentext.net

  • Snap at http://www.snap.com

  • WebCrawler at http://webcrawler.com

  • World Wide Web Worm at http://www.goto.com

  • Yahoo at http://www.yahoo.com

  • DejaNews at http://www.dejanews.com (searches newsgroup postings)

  • People Search at http://people.yahoo.com/ (has online white-page directories for telephone numbers, addresses, e-mail addresses, etc.)

  • Big Yellow at http://www1.bigyellow.com (has electronic yellow pages)

  • WebSeer at http://webseer.cs.uchicago.edu (has a huge database of graphics)

  • All4one at http://www.all4one.com allows simultaneous searching of 4 search engines.


Other strategies for your searches


Don't limit your Internet searching to using search engines. Be creative and think about which Internet sites might have the information you are looking for. For example, might any of the following lead you to the sites that will provide the information you are looking for?

Our OWL also has a list of starting points for Internet research (at http://owl.english.purdue.edu/internet/tools/research.html) grouped by different fields of interest, and some other general reference tools (at http://owl.english.purdue.edu/internet/resources/sourceofinfo.html) for searching the web that may help you to find what you're looking for.



  • Looking for information about job opportunities? Look at some of the sites listing job vacancies. Try university websites that sometimes list jobs through their placement offices, or try professional organizations which also sometimes list jobs in that field. Or look through the websites of various large companies because they usually have a section on job opportunities in their company.

  • Looking for information likely to be discussed on newsgroups or chat rooms? Look through the lists of newsgroups or use a search engine like DejaVu.

  • Looking for information about a current topic? Check the newspaper and current newsmagazine sites. Most have a search engine for articles in their publications.

  • Looking for data that might have been collected on a government site? Start with sites such as the Library of Congress (at http://www.loc.gov/) or The White House (at http://www.whitehouse.gov/). If the data concerns a state or a foreign country, is there a site for that political entity?

This site (at http://www.virtualsalt.com/evalu8it.htm) has some valuable information on how to evaluate Internet resources. For more help, see the handout on Evaluating Sources of Information at http://owl.english.purdue.edu/handouts/research/r_evalsource.html.

(This document written by M. Harris, August 1997, revised July 1999, revised again in June 2001)






The following information must remain intact on every handout printed for distribution.

This page is located at http://owl.english.purdue.edu/handouts/print/research/r_websearch2.html

Copyright ©1995-2004 by OWL at Purdue University and Purdue University. All rights reserved.


Use of this site, including printing and distributing our handouts, constitutes acceptance of our terms and conditions of fair use, available at
http://owl.english.purdue.edu/lab/fairuse.html.

To contact OWL, please visit our contact information page at


http://owl.english.purdue.edu/lab/contact.html to find the right person to call or email.

http://owl.english.purdue.edu/handouts/research/r_evalsource.html


Getting Started


There’s a lot of information out there, not all of which is trustworthy.

We live in an information age. The quantity of information available is so staggering that we cannot know everything about a subject. For example, it’s estimated that anyone attempting to research what’s known about depression would have to read over 100,000 studies on the subject. And there’s the problem of trying to decide which studies have produced reliable results.

Similarly, for information on other topics, there’s not only a huge quantity out there but a very uneven level of quality. You don’t want to rely on the news in the headlines of sensational tabloids near supermarket checkout counters, and it’s just as hard to know how much to accept of what’s in all the books, magazines, pamphlets, newspapers, journals, brochures, Web sites, and various media reports that are available. People want to convince you to buy their products, agree with their opinions, rely on their data, vote for their candidate, consider their perspective, or accept them as experts. In short, you have to sift and make decisions all the time, and you want to make responsible choices that you won’t regret.

Evaluating sources is an important skill we need all the time. It’s been called an art as well as work—much of which is detective work. You have to decide where to look, what clues to search for, and what to accept. You may be overwhelmed with too much information or too little. The temptation is to accept whatever you find. But don’t be tempted. Learning how to evaluate effectively is a skill you need both for your course papers and your life.

When writing research papers, you will also be evaluating sources as you search for information. You will need to make decisions about what to search for, where to look, and once you’ve found material on your topic, whether to use it in your paper.

 

Ask your self some questions before you start.


What kind of information are you looking for?

Do you want facts? Opinions? News reports? Research studies? Analyses? Personal reflections? History?



Where would be a likely place to look?

Which sources are likely to be most useful to you? Libraries? The Internet? Academic periodicals? Newspapers? Government records?

If, for example, you searching for information on some current event, a reliable newspaper like the NY Times will be a useful source. Are you searching for statistics on some aspect of the U.S. population? Then, start with documents such as United States census reports. Do you want some scholarly interpretations of literature? If so, academic periodicals and books are likely to have what you’re looking for. Want to know about commercial products? Will those companies have Web sites with information? Are you searching for local history? Then a county library, government office, or local newspaper archive is likely to be the most useful.

http://owl.english.purdue.edu/handouts/print/research/r_evalsource3.html


Brought to you by the Purdue University Online Writing Lab at http://owl.english.purdue.edu


Getting Started at http://owl.english.purdue.edu/handouts/research/r_evalsource.html

Evaluating a Bibliographic Citation at http://owl.english.purdue.edu/handouts/research/r_evalsource2.html

Evaluating Content in the Source


Evaluating Internet Sources at http://owl.english.purdue.edu/handouts/research/r_evalsource4.html

Further Resources at http://owl.english.purdue.edu/handouts/research/r_evalsource5.html



After you have asked yourself some questions about the citation and determined that it’s worth your time to find and read the source, you can evaluate the material in the source as you read through it.



  1. Read the preface.

What does the author want to accomplish?

  1. Browse through the table of contents and the index.

This will give you an overview of the source. Is your topic covered in enough depth to be helpful? If you don’t find your topic discussed, try searching for some synonyms in the index.

  1. Check for a list of references or other citations that look as if they will lead you to related material that would be good sources.

  2. Determine the intended audience. Are you the intended audience? Consider the tone, style, level of information, and assumptions the author makes about the reader. Are they appropriate for your needs?

  3. Try to determine if the content of the source is fact, opinion, or propaganda.

If you think the source is offering facts, are the sources for those facts clearly indicated?

Do you think there’s enough evidence offered? Is the coverage comprehensive?

(As you learn more and more about your topic, you will notice that this gets easier as you become more of an expert. )

Is the language objective or emotional?

Are there broad generalizations that overstate or oversimplify the matter?

Does the author use a good mix of primary and secondary sources for information?

If the source is opinion, does the author offer sound reasons for adopting that stance? (Consider again those questions about the author. Is this person reputable?)


  1. Check for accuracy.

How timely is the source? Is source 20 years out of date? Some information becomes dated when new research is available, but other older sources of information can be quite sound 50 or 100 years later.

Do some cross-checking. Can you find some of the same information given elsewhere?

How credible is the author? If the document is anonymous, what do you know about the organization?

Are there vague or sweeping generalizations that aren’t backed up with evidence?

Are arguments very one-sided with no acknowledgement of other viewpoints?





The following information must remain intact on every handout printed for distribution.

This page is located at http://owl.english.purdue.edu/handouts/print/research/r_evalsource3.html

Copyright ©1995-2004 by OWL at Purdue University and Purdue University. All rights reserved.
Use of this site, including printing and distributing our handouts, constitutes acceptance of our terms and conditions of fair use, available at
http://owl.english.purdue.edu/lab/fairuse.html.

To contact OWL, please visit our contact information page at


http://owl.english.purdue.edu/lab/contact.html to find the right person to call or email.


http://owl.english.purdue.edu/handouts/research/r_evalsource4.html

Evaluating Internet Sources


Further Resources 

Internet sources can be very timely and very useful, but they should not be your sole source of information because there are also books, journals, government publications, brochures, newspapers, etc. to read, and knowledgeable people to interview.

Evaluating Internet sources is particularly difficult because anyone can put up anything he or she wants to on the Internet. There is no way to monitor what’s there and no fact checking, though there are some site ratings you can check.

Be sure to document what you find on the Internet in such a way that others can locate what you found. This is most easily done when you accessed the data. Include the date you accessed the material since it can be changed or updated later on. Be sure to browse around on the Web site to be sure you know who the author is, what the sponsoring organization is, and so on so that you can cite the source fully and so that you can evaluate it properly before including it in your paper.


Authorship


-Is there an author or organization clearly indicated? If there’s an author, go back to the questions listed above about authors and ask yourself how reputable this person is. Can the author be contacted? (If an e-mail address is given, you can contact that person or look up the address by using the "finger" command.)

-What can you find out about the author?

If there is no information on the site, use a search engine or search Usenet. You may find the author’s homepage or other documents which mention this person. Or look up the person on the Internet Directory of Published Writers (http://www.writers.net). If the person is associated with a university, look at the university Web site.

-If there is an organization sponsoring the page, what can you learn about the organization and who they are?

(You can search the site by following links to its home page or going back to a previous level on the site by eliminating the last part of the address, after a "/" mark or a period. Another way to find the organization is to go to the View menu at the top of your Web browser and open the Document Information window where the owner of the document is listed.)

Does the organization take responsibility for what’s on the site? Does it monitor or review what’s on the site? Look at the address for the site. Does it end in .edu, indicating that it’s an educational institution? If it has .gov, it should be fairly objective government-sponsored material. Addresses with .org are usually non-profit organizations that are advocacy groups. (The Sierra Club is an example of an advocacy group. Their postings will conform to their goals of environmental preservation. Information posted by advocacy groups may be accurate but not entirely objective.) If the site has a .com address, it’s most likely promoting or selling something.


Accuracy of information


-Is there documentation to indicate the source of the information? There may be a link to the original source of the information.

-Can you tell how well researched the information is?

-Are criteria for including information offered?

-Is there a bibliography or links to other useful sites? Has the author considered information on those sites or considered viewpoints represented there?

-Is the information current? When was it updated? (You can check at the bottom for a "last revised" date and/or notice if there are numerous dead links on the site.)

-Is there any indication of bias on the site?

-Does the site have any credentials such as being rated by a reputable rating group? If you see a high rating, is that because of the soundness of the content or the quality of the design? ( An attractive page is not a reason for accepting its information as reliable.)

Goals of the site


-What is the purpose of the site? To provide information? Advertise? Persuade?

-Are the goals of the site clearly indicated?

-Who is the intended audience?

-Is there a lot of flash and color and gimmicks to attract attention? Is that masking a lack of sound information or a blatant attempt to get you to do or buy something?


Access


-How did you find the site? Were there links from reputable sites? From ads? If you found the site through a search engine, that means only that the site has the words in the topic you are researching prominently placed or used with great frequency. If you found the site by browsing through a subject directory, that may mean only that someone at that site registered it with that directory. 


База данных защищена авторским правом ©shkola.of.by 2016
звярнуцца да адміністрацыі

    Галоўная старонка