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Agriculture Graduate Student Orientation: Advanced Search Skills

A resource guide that is full of helpful information for Ag Grad students.

Tips for Searching Databases

Most of the databases that you use to look for articles will use Boolean searching, so it's important for you to understand how it works and how the operators function. Interfaces differ between databases, but Boolean searching always works the same way. If you aren't familiar with Boolean searching and you only have 30 seconds, this is the video to watch.

Boolean Example

Boolean Operators

There are three Boolean operators that are used to connect terms and tell databases how and what to search for: AND, OR, NOT.

AND is to combine terms, usually unlike terms/concepts. AND narrows a search. Example: diet AND income

OR is typically used with synonyms and similar terms. OR broadens a search. Example: income OR low-income

NOT is used to exclude something. Example: low-income NOT covid

We use parentheses to help group parts of the search query, especially when we have several parts, and to tell the database the order of the query. Think about the search query as a mathematical equation.

All put together, they look like this:  diet AND (income OR low-incomeNOT covid

Truncation allows you to find different endings to a word. The symbol in many databases is: *

Example: teenage* captures teenager, teenagers, teenaged.

Be careful not to truncate too far into the word. For example: car*  will capture car, cardiology, carbohydrate, caramel, carabidae, carassius, and thousands more words. carbohydrat* would be a better way to truncate.

In Pubmed

At least four characters must be provided in the truncated term.

The truncated term must be the last word in the phrase.

Truncation turns off automatic term mapping and the process that includes the MeSH term and any specific terms indented under that term in the MeSH hierarchy. For example, heart attack* will not map to the MeSH term Myocardial Infarction or include any of the more specific terms, e.g., Myocardial Stunning; Shock, Cardiogenic."

Wildcards are symbols used within a word to represent a letter for a variation on spelling. While not every database uses them anymore, for those that do, the symbol is often ? or $, though always best to check the database documentation.

Example: behavio$r captures both the American spelling, behavior, and the British spelling, behaviour

In PubMed

"To search for all terms that begin with a word, enter the word followed by an asterisk (*): the wildcard character. 

To search for a phrase including a truncated term, use the following formats:

  • Enclose the phrase in double quotes: "breast feed*"
  • Use a search tag: breast feed*[tiab]
  • Use a hyphen: breast-feed* "
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