Database 101: Search Databases - Tips & Tricks

Boolean Operators connect multiple search terms to either narrow or broaden your results.  Boolean logic defines the relationship between keywords, making your searches more precise and productive.

AND  |  OR  |  NOT

(In the diagrams below, the returns are blue)

AND (+ )is a limiter,
helps to narrow search.

Retrieves only records containing ALL the search terms.

Examples:
"stock market" and trading
"high school students" and "test anxiety"

OR is an expander,
helps to broaden search

Returns records containing either one or both terms.  Results will may include ANY of the search terms requested.  Useful when expressing similar concepts, synonyms.

Examples: 
violence or aggression
reindeer or caribou

NOT (-) is a limiter,
helps to narrow search

Excludes records with the 2nd search term.

Example:
Mexico not "New Mexico"
Mexico not City
Dementia not Alzheimer's

NESTING

You can NEST terms to further refine your search. Remember that boolean is mathematical logic - think of them as sets.  This allows you to combine several queries into one comprehensive search statement. 

Use parenthesis to define sub-sets.

Example:
(smoking or tobacco) and cancer
"genetic engineering" AND (ethics OR morality) NOT cloning

Invest time developing your search terms.
Pre-reading is a valuable step - it provides context , concepts and jargon.
You need information to find information.

Look closely at your assignment. 
Are there guiding questions you can use to construct a search?

Keywords - Descriptors - Topics - Subjects

If you don't get a good return, try new keywords.
 When you find a good article, pay close attention to the database record -
what keywords and subject headings has the database assigned?
What are the key concepts in your research question?
Adjust as needed. 
 

How do I find keywords for my search?

• PRESEARCH!!!

Ebsco Discovery Service  produces Research Starters for major topics.  This will be the first record returned. 
Gale Virtual Reference Library - read for overview, context
Wikepedia (a place to start for who, what, where, when)
Relevant material in your textbook.
Brainstorm with your teacher, librarians, fellow students.

• When you find a relevant article, mine it for keywords - concepts, jargon...  Keep a running list of terminology
• Check an online thesaurus and subject area dictionaries.  Many databases have their own built-in thesaurus to browse for descriptors that will match your topic.  (Check help screen.)

• Keywords are natural language, which the database searches for in the abstract and the full text of the article.  Keyword searching is the most like Google searching, and usually yields the most results, 
  Keyword searching allows you to combine terms.
  Start your search using keywords.
• Subject headings are pre-determined terms assigned by the database. Using subject headings will return the most relevant articles, but it assumes a more sophisticated knowledge of the topic.
  Start with keyword search and make note of what subject headings appear in the record return, then enter those terms in a revised search.

Truncation expands your search by returning results with multiple endings of a root word. 

Also called stemming.

Examples:

teen*  teen, teens, teenager

psych*  psychology, psychiatry, psychological, psychiatric, psychologist, psychoanalytical, etc...

Useful for alternative spelling. 

Example:  color and colour

Although truncation symbols may vary by databases (check help screen), the most commonly used is *.

Enclosing a phrase in double quotation marks or parentheses tells the database to search for those words together in that exact order.

Examples:

"global warming"
"climate change"
 

Publication type

Peer reviewed (scholarly) journals

Date range

Some advanced databases allow limiting by methodology

Define concepts and specify information types

A few examples:

[topic] and political aspects and policy

[topic] and "religious aspects" or morality

[topic] and personal narrative* or memoir

[topic] and interview*

[topic]  and (laws or regulations or cases)

[topic] and statistics or data

[topic] and "public opinion" or polls