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Environmental Science 101: Keyword Searching Tips

Choosing Keywords

The most important part of your search is deciding on the words you will use to search with. These words are commonly referred to as keywords or search terms.

If you are not searching for a specific title or author, think about the key concepts of your search. For example, if your topic is "how television violence affects children" you might search for: television, violence, children.

It's also helpful to think about synonyms for your keywords. For example, if you were searching for something on teens and drinking, you might also use the words: adolescence, adolescents, teenagers, young adults, alcohol, alcohol abuse, and so on.

Narrowing or Broadening Your Search Using Boolean Operators (AND, OR, NOT)

Boolean operators are used to connect search terms in ways that narrow or broaden your search. There are three commonly used Boolean operators: AND, OR, and NOT.


  • The AND operator retrieves all records that contain all of the search terms thus, narrowing your search. Combining two or more terms with the AND operator requires that all the terms occur in the same record.

  This is a diagram of a search using AND. If you search for cat AND dog, you will only get results that include information about both cats  
  and dogs. Using AND is a good way to narrow your search.

  • The OR operator retrieves all records that contain at least one of the search terms. The OR operator thus expands a search. Combining a set of terms with the OR operator requires that at least one term be present in a record in order to retrieve that entry. For example, a search for China or Japan retrieves all records containing one or both of those terms. 


This is a diagram of a search using OR. If you search for cat OR dog, you'll get any information that mentions either cat or dog. This is a good way to broaden your search.


  • The NOT operator excludes a term or group of terms from your search.

This is a diagram of a search using NOT. If you search for cat NOT dog, you'll only get results about cat, and no results about dog. This is another good way to narrow your search.

Truncation and Wildcards

Computer databases are very literal. Every keyword that is entered into a search must appear exactly as typed. Of course, sometimes words have different spellings, and there are different forms of the word, such as singular and plural forms and different suffixes. If you choose the wrong tense of a verb or the variant spelling of a keyword, you could miss relevant records.

One way to ensure retrieving all variations of a word is to use truncation or wildcards. Most databases have symbols that can be used to truncate or add wildcards to keyword searches. The symbol used by the databases may vary, therefore you will need to check the Help screens to determine which symbols are used. Common truncation/wildcard symbols are: *, ?, #, $, + and !.

  • Here's an example of truncation using the asterisk ( * ).


Religio* retrieves

  • RELIGION
  • RELIGIONS
  • RELIGIONIST
  • RELIGIONIZE
  • RELIGIOSITY
  • RELIGIOUS
  • RELIGIOUSLY

  • Here's an example of a wildcard using the asterisk.


Wom*n retrieves

  • WOMAN
  • WOMEN