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Boolean Searching
A simple lesson in Boolean searching is available and advisable to
those who are unfamiliar with this method. It is possible to compose
some complex search expressions using Boolean logic on this search
system. To do so, use the following terms:
'AND' (Boolean AND)
'OR' (Boolean OR)
'AND NOT' (Boolean NOT)
Parentheses can also be used when conducting an advanced search.
For example: art AND (school OR college) - this
expresses a search for records containing information about art
schools or colleges.
Boolean logic is essentially very simple. When used in constructing
a search expression, it can be very useful in specifying exactly what
information you want. The basis of Boolean logic can be illustrated by
the following diagrams:
Boolean 'AND'

This is expressed as 'blue AND yellow' in a
search.
When using AND in this search expression, results retrieved
will contain both blue and yellow information. The results will not
include those documents containing only blue or only yellow
information. In the diagram the documents retrieved by using this
search expression are contained within the green area.
EXAMPLE: art AND schools
This will retrieve all records containing both keywords art and
schools.
Boolean 'OR'

This is expressed as 'blue OR yellow' in a
search.
When using OR in this search expression, results retrieved
will contain either blue information, or yellow information, or blue
and yellow information together. Such a search will not merely
retrieve documents containing only blue information or only yellow
information. In the diagram the documents retrieved by using this
search expression are contained within all the colour areas.
EXAMPLE: ceramics OR pottery
This will retrieve all records containing the keywords ceramics
or pottery, as well as those containing both.
Boolean 'NOT'

This is expressed as 'blue NOT yellow' in a
search.
When using NOT in this search expression, results will
contain only blue. The NOT operator will exclude yellow
completely and thus any green information will be excluded also. It is
important, therefore, to be careful when using this operator in order
to avoid hindering your search. In this diagram the documents
retrieved by using this search expression are contained within the
blue area.
EXAMPLE: film NOT photography
This will retrieve all records containing the keyword film but
not the keyword photography.
http://adam.ac.uk/info/boolean.html |