InfoTrac
Databases: Using Proximity Operators
Definition
- Proximity operators are used to
search for words and/or phrases that you expects to occur within a
certain distance of each other in text.
- Example: The words
"doctor" and "examination" could occur in the
following ways in relation to each other.
- The examination by
the doctor was ....
- The doctor
conducted the examination in the ....
- The court questioned
whether the examination that was conducted by the
doctor was ...
Operator
Construction
- Proximity operators contain two
components:
- A letter that indicates the
direction of the relationship between 2 words and/or
phrases.
- A number to specify the
expected maximum distance in words between 2 words and/or
phrases.
Operators in
InfoTrac
- Wn
(Example: w7)
- Usage: The
W
(within) operator finds records in which the word that
follows the operatorWn
must occur within n
words after the word
that precedes the operator
- Example: examination
W7
doctor finds:
- The examination by
the doctor was ....
- The court questioned
whether the examination that was conducted by the
doctor was ...
- The doctor
conducted the examination in the ....
- Nn
(Example:
n7)
- Usage: The
N
(near) operator finds records in which the words on
either side of the operator Nn
must occur within n
words from each
other.
- Example: examination
N7
doctor finds:
- The examination by
the doctor was ....
- The doctor
conducted the examination in the ....
- The court questioned
whether the examination that was conducted by the
doctor was ..
General Rules
for Usage
- Proximity operators can be
used only when searching indexes made up of individual words,
such as the following indexes:
- Title
- Abstracts
- Text
- Subjects
- The operators are most
useful when used to search indexes of large areas of text,
such as an abstract or words in text index.
- Proximity operators can only be
used between two words and/or phrases
- They can not be used between a
word and an expression within nesting operators
(parentheses):
- Example: The following is
not valid:
- veterinarians
w10
(cats or dogs)
- It can be rewritten to work
in the following format:
- veterinarians
w10
cats or veterinarians w10
dogs