EBP and the Library: Creating and running a search

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Choosing Search Terms

Once you have developed an answerable question, identify the main ideas.  Unlike a search engine, databases are literal and can't interpret questions.  It's up to you to choose the search terms or keywords to begin your search.

Before you start searching, write down some initial words that you know about your topic.  Focus on keywords that best describe the subject matter.

As you continue to search, keep track of new words you find related to your topic. These may include subject headings.  Subject headings are specific, predefined labels used to describe the content of an article.  While subject headings will be used consistently throughout one database, they will not be exactly the same for EVERY database. 

Remember, searching is a process.  You probably won't find best results on your first try, and that's normal!  Make changes to your search strategy and try again.  Keep track of your changes so you know what worked and what didn't.  Using the terms most relevant to your topic will help you find the most relevant results.

Creating a Search String

Once you have your keywords, you'll create a search string.  A search string is a combination of keywords, Boolean Operators (AND, OR, NOT) and other search modifiers such as quotation marks, parentheses, and truncation.

AND: Searches for both terms, narrows the search.

     Example: (injury AND concussion)

OR: Searches for either term, broadens the search.

     Example: (diet OR nutrition)

NOT:  Searches for one term, but not the other, narrowing the search to more relevant results.

     Example: (shingles NOT construction)

Quotation marks:  Searches for the exact phrase inside the quotes, narrows the search.

    Example: "risk factors"

Parentheses: Used to keep similar terms together as the search string becomes more complex.

     Example: (college OR university) students AND (anxiety OR stress)

Truncation: May differ by database, but an asterisk (*) is frequently used as a wildcard to search for all variations of a word.  It broadens the results, sometimes too much.

     Example: injur* will bring back results including the words injure, injury, injured, injuries, injurious, injuring

Boolean Operators (3:43)

Boolean operators (AND, OR, NOT) are used to broaden or narrow our search results.  To see an example of how this works, please watch this short video.

Search Process and Keywords Overview (4:47)

Activity: Search in PubMed using Clinical Queries