Improving  Keyword Searches 

Most students, whether they search library catalogs, article databases, or Google, tend to use keyword searching.  There are two main reasons for that: a. keyword searches allow more flexibility in the terms you may use, and b. some search tools do not allow subject searches, or if they do, they can be poorly designed.

Since keyword is the type of search you'll be performing most of the time, here are some techniques that make this type of search the most efficient and effective:

• The very first thing you need to do in a keyword search is identify the two or three most meaningful words that describe your research topic.
  
      Example:
  
      Research topic: Did Tyrannosaurus Rex have feathers?
      Keywords: Tyrannosaurus Rex, feathers.
   
• Avoid typing in unnecessary words such as "causes", "relationship", "pros and cons" etc.  These words can limit your search a lot and may exclude important results.
   
• Remember that keyword searches do not care for prepositions such as: at, to, on, in, with, etc.  Use the Boolean connectors (and, or, not) discussed below instead!
   
• There are additional important techniques you should take advantage of to refine your search results. These techniques include:

Phrase Searching:

Use quotation marks " "

Examples:

"acid rain"

"Martin Luther King, Jr."

Truncation or wildcard

Truncation is a technique that enables you to look for a word and any of its possible endings. Using truncation is also called using a "wildcard" because it allows you to insert a symbol (usually an asterisk * , or ?) as a wild card at the end of a word.

Different databases or search engines may use different symbols for truncation. Common symbols include * and ? . These symbols tell the computer to look for the root of the word and all alternate word endings, thus expanding your search results.

For example, a search on the word adolescen*  would also search for adolescent adolescents adolescence

An important note on truncation:

When you truncate, make sure you place the * symbol at the right place!  For instance, typing in "adolescents*" is incorrect, since the database has no other endings to add to your word!

             Boolean logic

Boolean logic, particularly the use of the Boolean operator AND, is the most important technique for limiting results in any database or search engine search. The principal Boolean operators are:

        Here is a graphic representation of the function of Boolean operators:

                                            (A)                                                                                            (B)                                                            

In diagram (A) you can see in blue the results of a search that uses the Boolean connector AND. AND, as in the search "computers AND education", narrows  results. It is often used for linking together different concepts. Think of AND as only if also.

In diagram (B) you can see in blue how a search that uses OR really expands the results. Think of OR as more.  Basically, use the Boolean OR to combine synonyms or like concepts. For example:  teenager* OR adolescen*  (I am using truncation in this example, too!)

In diagram (C), you see the results of a search that uses NOT to get rid of an unwanted keyword.  For example: computer* AND education NOT higher
 

A few important notes on Boolean operators: Boolean logic is effective only in Keyword searching. Remember!  Subject searches use specific subject headings/descriptors!   You should always use a parenthesis (   ) around those items that you combine with OR.  If you skip this step, the database will not know which terms you wish to combine with "OR" and will most likely retrieve lots of irrelevant results!            Example:            (women OR females) AND sports You may use as many of these Boolean operators as necessary in a single search statement.  Example: (women OR females) AND sports NOT basketball   Be aware that each database and search engine may use Boolean logic in a different way. For example:     -- Our library Catalog uses "AND NOT" to exclude terms,  whereas article databases such as the Ebsco (we'll learn about Ebsco later on...) usually use "NOT".     -- In Yahoo and other search engines you need to use the plus sign "+" instead of the Boolean "AND."

To practice on your own, try the following two exercises:

1.  Do a search on hybrid  cars also including in the results the word electric cars.  Use the Booleans AND, OR and also truncation.  Click  here for an answer.

2.  You are doing research on the cost of higher education.  What are some different searches you could try for the topic?  Click here for an answer.