Boolean Searching

BASIC BOOLEAN SEARCHING

Boolean operators (or logical connectors)-- AND, OR, and NOT-- are used to link together keywords when creating a search statement. Boolean operators may be used in most databases, and are used to broaden or narrow a search.

Always read screens carefully (especially HELP screens) or ask for assistance at the reference desk.

AND Keywords combined with AND will retrieve records only where both terms appear.
Example: social security AND reform (AND is used to narrow a search)
   
OR Keywords combined with OR will retrieve records where either one or both terms appear.
Example: blacks OR african americans (OR is used to broaden a search)
   
NOT

Keywords combined with NOT will retrieve records with the first term but not the second.
Example: depression NOT mental health (NOT is used to narrow a search)

 

USING BOOLEAN OPERATORS IN A SEARCH STATEMENT

1. State your topic in one sentence: race as a factor in death penalty sentencing
2. Break your topic down into key concepts or words:
concept 1: race concept 2: death penalty
3. Connect these words with the appropriate Boolean operators:
race and death penalty
4. Broaden your search using synonyms and/or variant spellings. Use parentheses if using two or more Boolean operators in a single search statement:
race and (death penalty or capital punishment)

 

TRUNCATION AND PLURALS

Many databases offer a searching option called truncation. By attaching a designated symbol to the end of a word or word root the computer searches for plurals and/or variations of the word. The symbol is often a* (consult help screens in database to verify). Do not place a truncation symbol after a common word root like "tele" or "man" as you will retrieve too many irrelevant hits.

Example: hospi* will retrieve hospice, hospices, hospital, hospitals, hospitable, hospitality, etc.

Example: downsiz* and corporat* will retrieve the same results as: (downsize or downsizing or downsized) and (corporate or corporation or corporations).

Example: employee* Will retrieve both singular and plural, employee and employees.