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How to use Boolean Operators in Queries – What do they mean?

Cate Farrall
posted this on October 23, 2012 14:17

Boolean Operators

Boolean operators are widely used to build search queries.  They are logical blocks that tell a search engine what to include, exclude or combine when looking for results.

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In the notes you’ll find ideas on how and when to use the operators to best effect.  You can download this information as a pdf (click on the link at the bottom of the page).

It is good practice to always include the operators (even AND) and to write them in upper case letters.  This will make it easier to read and understand complex queries.

For more details on using these operators in the various parts of the Digimind platform, please read this article.

AND

AND is used to include both keywords in a search.  This is useful for combining words to focus your search query.  

“Iggy Pop” AND jazz = this will give me results that contain both Iggy Pop and jazz.

OR

OR is used to indicate that you don’t mind which of the words appears in the article.

jazz OR blues = this will bring back articles that talk about either jazz or the blues, or both.

NOT

NOT will exclude words from the results.  This will help to cut down some noise, or information that is not pertinent to my needs.

Iggy Pop AND jazz NOT The Stooges = this will eliminate any mention of The Stooges from the results, helping me to get only articles on jazz.

Quotation Marks “ “

Quotation marks are used to define words that must be present in the article as a group.  The words inside the quotation marks, including spaces and special characters (numbers, punctuation, symbols) will be treated as a complete and unbreakable set.

“Iggy Pop” AND jazz = this will treat the words “Iggy Pop” as a whole.  I will not receive articles that talk about pop music or the less famous jazz musician Ignatius Gennusa, who also went by the name Iggy.

Brackets ( )

Brackets give a structure to the query and are therefore useful for complex queries.  It is possible to create groups of words that can interact with others.

(“Iggy Pop” AND (jazz OR blues)) NOT (“The Stooges” OR punk OR rock)

Question Marks

Question marks act like a wild card or a joker.  They can be placed at any point in the word.  During the search the letter that has been replaced by the question mark can be substituted for any other character. 

s?ng = this will bring back results containing sing or song or sang or sung.

album? = this will bring back both album and albums.

Question marks should be used with caution, as depending on where you use them you may find they generate some results that are not exactly what you wanted.

If you use a question mark inside quotation marks, Digimind will treat the question mark as a question mark and look for words that really do contain a ?.

Asterix *

Asterix can only be used at the end of words.  They are also wild cards, but unlike the question mark, they will replace more than one letter.  They should be used with even more care than question marks.

drum* = this will bring back drum, drummer, drumming, drumset, drumstick, drumbeats, drumroll, drumbing, etc.

Tilde ~

The tilde is used to specify that the words should be no more than a specified distance from each other.  To use it, group the words together with quotation marks, then use ~ followed by a number.

“Iggy Pop jazz”~8 = the three words iggy, jazz and pop must have no more than 8 spaces between them, but can be in any order.

This is useful if I would like to find words in the same sentence (set a low number) or in the same paragraph (set a slightly higher number).

begin:

begin is used to indicate that the keywords must appear within the first 25% of the article.  To use it, write begin: followed by the keyword directly, without a space

begin:"Iggy Pop"

intitle:

intitle is used to limit the search to the title of the article only.  To use it, write intitle: followed directly by the keyword.

intitle:"Iggy Pop"