Combining Search Terms with Boolean Operators
Once you've identified your search terms (keywords) the next step is to test them out by searching a catalog or database. While some databases allow you to list all of your terms in a single search box, you will frequently retrieve better results if you use Boolean operators (AND, OR, NOT) to combine your terms. These operators allow you to communicate the relationship you want there to be among your search terms. The content below will explain why to use each operator and provide examples for how to use them in context.
Boolean AND Operator
Use to:
- Narrow your search results
- Tell the database that you need all of the terms to appear in the results
Example:
- media AND ethics AND confidentiality
The center triangle of the Venn diagram below indicates which results would match your search criteria. All of your search terms--media, ethics, and confidentiality--must be present for a source to be included in your results.
This is what search terms combined with AND look like in a database:
Boolean OR Operator
Use to:
- Broaden your search results
- Connect two or more similar concepts
- Tell the database that any of the search terms may be present in your results
Example:
- media OR journalism
The yellow highlighting in Venn diagram below indicates which results would match your search criteria. Your search results will include sources that mention media only, sources that mention journalism only, and sources that mention both media and journalism.
This is what search terms combined with OR look like in a database:
The OR operator is frequently used within a single search box to combine similar terms:
Boolean NOT Operator
Use to:
- Exclude terms from your search results
- Narrow your search results
Example:
- media NOT journalism
The yellow highlighting in Venn diagram below indicates which results would match your search criteria. Your search results will include only sources that mention media but will exclude any sources that mention journalism even if they also mention media.
This is what search terms combined with NOT look like in a database:
When using the NOT operator, be sure to use it only as the last element of your search so that the database doesn't exclude more than you intend.
What if I need help?
If you need assistance with your search, please reach out to the library for help.
Nesting, Phrase Searching, Truncation, and Wildcards
Nesting
What is Nesting?
Nesting is a means of using parentheses ( ) to further instruct a database search engine how you want your terms to be searched. Parentheses indicate to the search engine that you want particular search terms to be treated as a group. When using an Advanced Search screen in a database, each search box functions as a set of terms surrounded by parentheses.
Here's how you would use parentheses in conjunction with the Boolean OR and AND operators:
- The OR operator is typically placed between individual search terms inside of parentheses or a single search box.
- The AND operator is frequently placed in between two groups of parentheses.
Examples
- (media OR journalism) AND (ethics OR morals OR integrity) AND (confidentiality OR anonymity)
Phrase Searching
What is Phrase Searching?
Phrase searching is a means of searching for particular words in an exact order. You can search for words as a phrase by enclosing them on quotation marks (" ").
Examples
- "media ethics"
- "confidential source"
Truncation
What is Truncation?
Truncation is a means of searching for variant endings of words that share the same root. You can truncate any term by strategically dropping the ending of a word and replacing it with an asterisk (*).
Examples
- ethic* = ethics, ethical, ethically, ethicist, etc.
- anonym* = anonymous, anonymity, etc.
Be careful where you truncate a word so that you don't get irrelevant results. For instance, if you truncated journalism after the stem journal, you would get journaling along with journalist and journalism.
Wildcards
What are Wildcards?
Like truncation marks, wildcards are used to replace letters. The most common wildcard is the question mark (?), which is used inside of words to replace one or more characters. These are most helpful when dealing with variant spellings (e.g., American v. British spellings) or words that vary in spelling by only one letter.
Examples
- col?r = color, colour
- wom?n = woman, women
What if I need help?
If you need assistance with your search, please reach out to the library for help.
