| OCLC FirstSearch: Help |
Combining search terms (Boolean searching)
Use the Boolean operators AND, OR, and NOT to combine search terms when you need to expand or narrow a search. Use parentheses ( ) to specify the order in which terms will be combined. In the diagrams below, each circle represents a different search term. The portions retrieved in a search using these terms are shaded.
- AND operator
- OR operator
- NOT operator
- Parentheses (nesting)
- FirstSearch rules for processing a Boolean search
- Additional information
AND operator
AND retrieves only records that contain all search terms. Use this operator to narrow or limit a search.
nepal
AND holiday
| If you type: | FirstSearch searches for: |
|---|---|
| nepal AND holiday | only records containing both nepal and holiday |
| psychology AND menu AND design | only records containing all three search terms-- psychology, menu, and design |
OR operator
OR retrieves all records that contain one or both of the search terms. Use this operator to expand a search.
nepal
OR holiday
| If you type: | FirstSearch searches for: |
|---|---|
| nepal OR holiday | records containing nepal, records containing holiday, and records containing both nepal and holiday |
| psychology OR menu OR design | records containing psychology, records containing menu, records containing design, and records containing any combination of two or all three search terms |
NOT operator
NOT eliminates records that include a search term or group of search terms. Use this operator carefully to limit a search, as you may unintentionally eliminate relevant records.
nepal
NOT holiday
| If you type: | FirstSearch searches for: |
|---|---|
| nepal NOT holiday | records containing nepal which do not reference the search term holiday |
| psychology AND menu NOT design | records that contain both psychology and menu but do not include any reference to design |
Parentheses (nesting)
Group terms in parentheses to specify the order in which they will be combined. Without parentheses, terms will be combined in left-to-right order. For example, baseball and brewers or twins can be combined with parentheses to give you two distinctly different sets of results.
| If you type: | FirstSearch searches for: |
|---|---|
| baseball AND brewers OR twins | records containing both baseball and brewers, then records containing twins whether or not they contain baseball or brewers |
| (baseball AND brewers) OR twins | the same results as above because the parentheses group baseball and brewers first in left-to-right order |
| baseball AND (brewers OR twins) | records containing either brewers or twins or both; from this set of records, it then searches for records that contain baseball so that all records contain either brewers and baseball or twins and baseball or brewers and twins and baseball |
FirstSearch rules for processing a Boolean search
FirstSearch uses the following rules when processing a search containing AND, OR, or NOT:
- Process AND, OR, or NOT in left-to-right order unless ( ) are used .
- Process AND, OR, or NOT in ( ) first.
- If there is more than one ( ) in a search, process them in left-to-right order.
- If there are ( ) within ( ), process them from innermost to outermost.
- Process two words with only a space between them as if AND was between them and they were enclosed in ( ). For example, civil war OR stone river is processed as (civil AND war) OR (stone AND river).
- On the Advanced search screen, process AND, OR, or NOT typed in a search box as if they were enclosed in ( ). For example, if you type car AND safety in the first search box and air AND bag in the second search box, FirstSearch processes this as (car AND safety) AND (air AND bag).
Additional information
If you want to use AND, OR, or NOT as search terms instead of using them to combine other search terms, use quotation marks. For example, to search for a title containing the phrase night and day, type night "and" day or "night and day".