Thursday, February 21, 2008

Google

http://www.google.com/

Use Google when...

  • you are looking for a specific fact/person/event/narrow topic
  • your topic is made up of multiple ideas
  • you can't get enough of Google's link ranking of results
  • you like Google's specialized features such as spell checking, phone book and flight lookups, stock prices, etc.
  • you want to take advantage of Google's advanced search interface that lets you fill out a form to do a search targeted to your needs

Google is a general search engine that is everyone's favorite these days. It ranks results by the number of links from the largest number of pages also ranked high by the service. The more highly ranked pages that link to a certain page, the higher the linked-to page will be ranked by Google. This unique ranking system can be quite effective.

Special Features:

  • Returns results ranked by the number of links from a high number of pages ranked high by the service; high ranking pages are also determined by the number of links to them
  • In determining relevancy ranking, the engine also looks at various textual clues including linking text
  • Suggests an alternative search when search terms are misspelled.
  • Search results include sites from the Open Directory Project, offering an interesting mix of sites from the wider Web and those chosen by editors for inclusion into the directory. See also Google's own version, the Google Web Directory.
  • OR searching is supported if "OR" is typed in CAPS, e.g., university OR college; works only with multiple single words
  • For more refined searches, use quotations for phrases ("El Nino") or a minus sign (-) for the Boolean NOT
  • I'm feeling lucky option returns the top-ranked source for a query
  • Offers searching of Web pages in a number of languages; and the Google site can be set to display only the tips and instructions in a different language
  • Has a number of special search features, listed on its page about Google Web Search Features
  • Searches the deep Web for such information as:
  • Files in Portable Document Format, Microsoft Word, Excel, and PowerPoint, Rich Text Format and PostScript
  • Images, from the Advanced Web Search interface or from Google Image Search
  • Maps from Yahoo! or MapBlast (enter an address)
  • Phone book entry (enter first and last name, and city or zip)
  • Stock prices (enter a comapny's ticker symbol)
  • And lots more!

Drawbacks:

  • New Web pages will not appear in your results, as it takes time for the creators of other Web pages to link to new resources, and for this activity to be reflected at Google
  • Google results can be manipulated ("bombed") by people who maintain Web pages. Bloggers and others sometimes attempt to associate words with a link to a specific Web site to make a political or other point. For example, the search terms "miserable failure" point to the official George Bush site. This site may become the number one hit on Google, even though the words are not relevant to it.
  • A number of other issues are pointed out by librarian Gary Price in his piece, A Couple of Comments about Google

We will be using Google to learn a number of search techniques.

Exercise: Multiple concept search

Query: I'd like to learn more about Richard Nixon's resignation.

Search:

  1. Type: Nixon resignation [Google defaults to Boolean AND logic]
  2. Examine results for relevancy
  3. Note the related categories from the Google Web Directory listed at the top of the results screen

This is a good example of a search tool that defaults to AND logic. It wouldn't hurt to use the plus (+) sign in front of each term, +Nixon +resignation, but this is not necessary. However, if you want a common word such as "where" or "with," you should use a plus (+) sign, e.g., +where.

Exercise: Phrase Search

For another way to ensure that all your search terms appear in documents you retrieve, use phrase searching. Enclosing a phrase within quotation marks is a syntax that works on nearly all search engines on the Web.

Query: I'd like to see information on the movie Gone with the Wind.

Search: "Gone with the Wind" [capitalization is not necessary]

Exercise: Field Search

Field searching is a way to narrow your search to specific parts of the document or record. Google offers a variety of ways to use field searching to better focus your results. First, let's try a simple search that is not a field search.

Query: I'd like to see information on slavery.

Search: slavery

This is isn't the wisest search to do in a large, full-text database like Google because it brings back too many results.

Let's look into ways to focus our results by using field searching. We will try these searches using Google's basic search box. Keep in mind that most of Google's field search options are also available on their Advanced Search form that is even easier to use.

Search: intitle:slavery

This is a much better search. This search will look for slavery in the title field embedded within the HTML document. Notice how all the page titles contain the word slavery.

Search (c): inurl:slavery

This is also a good alternative search. This search will look for slavery in the URL of the file, e.g., in a subdirectory named slavery, or in a filename such as slavery.html. Notice how all the results contain the word slavery somewhere in the URL.

Exercise: Putting it all together: Phrase and Field Search

Query: I'd like information about the Mars rover missions from the NASA site.

Search: +"Mars rover" +site:nasa.gov

This is a nicely-focused search. It uses the plus (+) sign to be sure that all of our search terms appear on the retrieved documents. In addition, the phrase Mars Rover is enclosed in quotation marks, and we have narrowed our search to retrieve documents only from the NASA site.

If field searching appeals to you, Google offers a complete list of Advanced Search Operators that you can examine and try. Also, be sure to check out Google's Advanced Search page. There are many useful options there and filling out the form is easy. Remember: a focused search is more likely to bring you the results that you're looking for.

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