Basic Search Tips and Advanced Boolean Explained
Please feel free to refer to this guide while doing the exercises of this course.
BASIC SEARCHING EXAMPLES
• Requires words to searched as a phrase, in the exact order you type them.
Quotation marks
“ ” “working mothers”
”affirmative action”
• Search which versus that.
Common Words Only versus is searched on. Which and that are ignored.
Usually Ignored • To require common words to be searched:
+ or “ ”
to search them +which versus +that
”which versus that”
Excluding
-word “acute pancreatitis” diet –cat –dog –“pancreatic cancer”
-“phrase in quotes”
OR allows more than • OR requires at least one of the terms joined by it to appear somewhere in
one term the document, in any order.
OR
“african americans” OR blacks
ear OR nose OR throat
• The more words you enter connected by OR, the more documents you get.
Broadens the search..
dogs OR cats • USES:
allows pages with at o The OR operator is generally used to join similar, equivalent, or
least one of the terms synonymous concepts.
"global warming" OR "greenhouse effect"
AND (default) • AND is the default and only needs to be typed if you are using other
Boolean operators with ( ).
infopeople training
is logically the same as infopeople and training
dogs AND cats
• The more words you enter connected by AND, the fewer documents you
is the small overlap
get. All your words will be searched on
where both terms
• USES:
occur
o The AND operator is generally used to join different kinds of
concepts, different aspects of the question.
o "global warming" AND "sea level rise" AND california
Created by Joe Barker, Teaching Library, University of California, Berkeley
May be reproduced for non-profit educational purposes
Advanced Boolean Explained
OPERATOR WHAT IT DOES & WHEN TO USE IT
AND NOT • Excludes documents containing whatever follows it.
• The AND NOT operator is generally used after you have performed a
search, looked at the results, and determined that you do not want to see
pages containing some word or phrase.
• USES:
dogs AND NOT cats o The AND NOT operator should be used with extreme caution,
excludes pages that because it eliminates the entire page, and some pages may be of
mention cats, even if value to you for other information they contain. I almost never use
they also mention and not for this reason.
dogs o "global warming" AND "sea level rise" AND NOT california -
The first two terms must be somewhere and any page containing
california will be thrown out.
NEAR • Requires the term following it to occur within a certain proximity of the
dogs NEAR cats preceding word in the search. In Exalead.com, NEAR requires the terms
requires both terms, to be within 16 words of each other in either direction.
like AND, with the • Joining words by NEAR gives you fewer documents than AND, because
added requirement it requires the words to be closer together.
that they be within 16 • USES:
words of each other o The NEAR operator is used when you want to require that certain
Available in terms appear in the same sentence or paragraph of the document.
Exalead.com only o "global warming" NEAR "sea level rise" - Requires the two
phrases to occur within 16 words of each other, in either direction.
• Require the terms and operations that occur inside them to be searched
first. This is called "nesting."
( ) • Parentheses MUST BE USED to group terms joined by OR when there is
parentheses: any other Boolean operator in the search.
"Nesting" o "global warming" AND "sea level rise" AND (california OR
"pacific coast*") - Requires first two terms somewhere in all
documents, and either california or pacific coast.
• Parentheses also MUST BE USED with NEAR:
o ("global warming" NEAR "sea level rise") AND (california
OR "pacific coast*") - Requires sea level rise to be within 16
words of global warming; the rest can be anywhere in the pages.
The parentheses guarantee that the effect of near stops with sea
level rise.
You do not need or even want to get very complicated with Boolean searching in web searching.
Searching the web is free, and several simpler searches take less time than a humongous search.
Moreover, with complicated searches, you often don't know which parts of the search worked and
which did not. Simpler searches can more easily be compared with one another, and you know what
worked.
Created by Joe Barker, Teaching Library, University of California, Berkeley
May be reproduced for non-profit educational purposes
