|
What you type into an edit box depends on how precise you want your search to be. You can keep your search very simple by typing a single word or phrase. Or, for a more precise search, you can construct a string using advanced features, such as Boolean, word expansion, and near operators. Here’s how:
Boolean Operators
Boolean operators – and, or, and not – are used to combine search words and phrases, using Boolean algebra.
 |
| |
|
Examples:
And: If you type “meat and dairy” in the Article Text field, your results will show articles that contain the word meat and the word dairy.
Or: If you type “meat or dairy”, your results will show articles that contain the word meat or the word dairy, and possibly both.
Not: If you type “meat not dairy”, your results will show articles that contain the word meat but that do not contain the word dairy.
|
|
|
 |
Word Expansion Operators
Word expansion operators expand words or phrases to find similar words or phrases. Keep in mind that the use of these operators will help with your search, but it will probably also slow down the speed at which you receive results, because the way data is found becomes more complex. Following are descriptions and examples of the most commonly used word expansion operators:
Wildcard (single character: _ , one or more characters: % or *) – Use wildcard characters to find words containing letters in addition to those you type. Your wildcard character can be placed anywhere in a word – at the beginning, middle, or end – wherever you want to put a “placeholder” for additional letters. The _ symbol should be used when you need a placeholder for exactly one letter, and the % and * symbols should be used as a placeholder for one or more letters. Also, there should be no spaces before or after the wildcard character, and you should use at least two letters in conjunction with the wildcard character.
|
| |
|
Examples:
If you want to find information on sleep deprivation but can’t remember if deprivation is spelled with an a, e, i, or o after the r, you could type “sleep depr_vation”, and your results will show materials containing sleep deprivation.
To find words that begin with do, such as doctor, door, and donate, type:
do% or do*
To find words that end with tion, such as nation, fraction, and determination, type:
%tion or *tion
|
|
|
|
Stem ($) – The stem operator finds words with the same stem form. Place the stem character at the beginning of your query term, with no space in between.
|
| |
|
Example:
If you type “$fast” in the Article Title field, your results will show all articles whose titles contain the words fast, faster, fastest, fasts, fasting, or fasted.
|
|
|
|
Near Operator
Use the near operator to search based on the proximity of two or more query words or phrases. The syntax for the near operator is as follows:
near((word1, word2, …, wordn), num_words, order)
For word1 – n, specify words or phrases separated by commas.
For near queries with only two words or phrases, num_words is the number of words between them.
|
| |
|
Example:
To query on missile defense and 2002, where missile defense is no more than six words from 2002, type the following string:
near((missile defense, 2002), 6) |
|
|
|
For near queries with more than two words or phrases, num_words is the size of the biggest “clump” within which the specified words or phrases must appear. You can specify the size, between 1 and 100, of the clump (the default is 100).
|
| |
|
Example:
To query on dog, cat, and bird, where these three words fall within a group of 15 words, enter the following string:
near((dog, cat, bird), 15) |
|
|
|
If you want to search for terms in a particular order, you need to specify TRUE (the default is False).
|
| |
|
Example:
To search for the words Monday, Tuesday, and Wednesday – in that order –and where these three words fall within a group of 20 words, enter the following string:
near((Monday, Tuesday, Wednesday), 20, TRUE) |
|
|
|
Combining Operators
In addition to using operators individually to create a search string, you can also combine two or more to further refine your search. Use parentheses to group operations, as you would with simple algebra.
|
| |
|
Examples:
To find the words milk and dairy near each other and also with the word cheese somewhere in the article but not necessarily near milk and dairy, type the following string in the Article Text field:
near((milk, dairy), 5) and cheese
To find all forms of the word clean except for the word cleaning, type the following string:
$clean not cleaning
To find articles containing dog and care or cat and care, and possibly both, type the following string:
(dog and care) or (cat and care)
To find articles containing U.S. or United States and accounting or financial and software, type the following string:
(U.S. or US or United States) and (accounting or financial) and software |
|
|
|
|
Close Window
