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BECOME A POW!er SEARCHER: ABOUT DATABASES

Intro

College freshmen are expected to understand and use databases properly. So...

Let's get going!

Databases vs. the Internet

DATABASES

A database is an organized body of information, a set of controlled and related data.

  • Databases are efficient and convenient.
  • The information is controlled, structured and reliable.
  • The information often comes from renowned reference companies such as Gale, EBSCO, Wilson, etc.
  • Online databases are updated regularly.
  • There are different types of databases:Textual, Graphical, Numerical, Audio, Mixed/Multimedia

THE INTERNET

  • Great tool. Great for browsing. Can be greatly frustrating too. 
  • Reliability is a major issue. You must evaluate your results carefully.
  • The internet is not as free as it appears to be.  A lot of the relevant information you need is proprietary information and is accessible at a cost.

NOTE: Most databases and search engines will allow full or limited Boolean searching. Google and Yahoo also have directory searching as part of their services. Check them out!

Directories and Search engines

DIRECTORIES

  • Sites are selected and categorized by information specialists. The staff are often subject experts.
  • Best for browsing purposes than for searching.
  • Require large amount of human effort to develop and maintain.
  • Examples of popular directories include Yahoo, Librarians Index and the Open Directory Project.
  • MedLine Plus is an example of a subject-specific directory.
  • The value of directories: 

           1. Hand picked
           2. Allow for serendipitous discovery.

 

SEARCH ENGINES 

  • Automated programs, called web robots, spiders, worms, crawlers search and index web sites.
  • Search for words found in the title, URL, introductory paragraphs, or full-text of documents of all web sites indexed by the search engine.
  • Examples of popular search engines include Google, Yahoo and Bing.
  • The value of search engines:

            1. Access to huge amount of information.
            2. Allow full-text searching.

         (Adapted from: Dartmouth Biomedical Libraries )
 

     The triumvirate of search engines. 

     . Google    Yahoo!    Bing (MSN)  are basically the unique search engines out there.

     The others mostly "borrow" their searchware, index or results from them. 

     Who owns what on the internet? So far...

          Yahoo owns Delicious, Flickr                           
          Google owns Youtube, Picassa, Blogger       
          Microsoft owns Bing

    If you're interested in search engines, check this site: searchenginewatch.com

Boolean Operators and Databases

Both databases and search engines use and, or, not. But they use them differently and you must learn them.

Here is how you use the 3 operators with databases.


http://www.seriouslyconnected.co.uk/blog/boolean-helpful-tips-and-tools/

AND - All the search terms must appear in the results entries
More and more databases use the implicit "and" like most search engines do. This means that you do not have to write [and] as it is assumed you want all the words written in your query. When in doubt, write it out: and.
cognition and nutrition
cognition nutrition


OR
- Either one of both terms will be searched
You must write the words as is, in small letters.
"global warming" or "climate change"


NOT
- Excludes a term you don't want in your results
You must write the word as is, in small letters.
depression not treatments

Advanced Techniques

Truncation (* in EBSCO)
(also called stem searching)

To truncate means "to cut". Databases allow you to search for variations of a word by "cutting" the word down to its root or stem then by adding a symbol to replace all the possible combinations.

Databases may use different truncation symbols and EBSCO uses the asterix * symbol (the star).

E.g.,

[comp*] will retrieve computercomputerscomputerizedcomputing, etc.

[adolescen*] will retrieve adolescent, adolescents, adolescence

Wildcard (? or # in EBSCO)

. The wildcard symbol is used to replace one character within a search word. E.g., [ne?t] will retrieve neatnestnext. Different databases may use different symbols. heck the help section of the database to find out what symbol it uses.

Proximity operators expand your searches (in databases only, not with Google)
N (near) and W (within) are used to search terms that are in proximity to each other. Check if and how your search engine supports proximity searches.

E.g., N5 means you want to search the search terms within 5 words of each other > [tax N5 reform] will retrieve tax reform and reform of income tax
E.g., W8 means you want to search the terms within 8 words of each other and in that order > [tax W8 reform] reform will retrieve tax reform but not reform of income tax

Use of parentheses (   ) (in databases only, not with Google)
Most engines will execute your search query from left to right. The order of the operators in your query is important as the order of execution will be led by the AND operator, then by the OR operator and finally by the NOT operator. To control the execution of your query, use (parenthesis) to group search terms. 

The engine will first execute the operation within parenthesis then perform the other operations of your query in order. Databases will almost always allow you to use full boolean searching, including the use of parenthesis and other symbols.

E.g.,
jungle and (cats or felines)
(cats or dogs) and (contest or show)

((mouse OR rat) AND trap) OR mousetrap

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