Boolean Operators 

Boolean operators define the relationships between words or groups of words. 



AND, +

Narrow search and retrieve records containing all of the words it separates. 

OR , |

Broaden search and retrieve records containing any of the words it separates. The | (Pipe) can be used in lieu of 'or', eg: mouse | mice | rat is equivalent to mouse or mice or rat 

NOT , -

Narrow search and retrieve records that do not contain the term following it. 

( )

Group words or phrases when combining Boolean phrases and to show the order in which relationships should be considered, eg: (mouse or mice) and (gene or pseudogene) 

Note: Search queries containing several operators search in the following order: 

( )

To ensure that a search containing different operators performs as you intend, use parentheses,
eg: calder and (painting not (sculpture or mobiles)) 

Proximity Searching 

Proximity searches limit the number of words between your search terms. 



no operator

Find words as a phrase, eg: life stage transitions retrieves records containing the three words immediately adjacent to one another and in the same order. 


Find words within a specified radius, eg: (women) within 5 (violence) retrieves records that contain women and violence in any order and within a five word radius of one other. Any number may be used to determine the proximity radius


Find words within 10 words of each other, eg: women near violence retrieves records that contain women and violence in any order with up to 9 words in between. Note: near is the same as within 10.


Finds words in a relative order, eg: social before security. Note: adjacency is not implied.


Finds words that contain words in the relative order specified with the after expression, eg: scope after science. Note: adjacency is not implied.

Note: Use double quotes " " to search for "near", "before", or "after", eg: "near death" experience

Wildcard Symbols 

Wildcard symbols can expand the scope of your search.




Truncation. This expands a search term to include all forms of a root word, eg: patent* retrieves patent, patents, patentable, patented, etc.


Multi-character wildcard for finding alternative spellings. Use to indicate an unlimited number of characters within a word, eg: h*ophilia retrieves haemophilia as well as hemophilia, and behavi*r retrieves behaviour or behavior.


Single-character wildcard for finding alternative spellings. The ? represents a single character; two ?? represent two characters; three ??? represent three characters, and so on. Use within or at the end of a word, eg: wom?n finds woman as well as women, and carbon fib?? finds carbon fiber or carbon fibre.

Note: Only words with characters equal to the number of ?'s present are retrieved, eg: cell? retrieves cells and cello but not cell.

Tip: When looking for singular and plural forms of short words that have a common root, such as cell, the truncation symbol may retrieve too many irrelevant words, while the wildcard symbol may retrieve too few words. In such a case, do not use wildcards and instead OR together the forms of the word you want, eg: cell or cells.