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Using Boolean Operators to Search AgeLine


The search engine for AgeLine has been designed to use Boolean logic for search queries to produce results targeted to a searcher's needs. With the search engine for the web version of AgeLine, most of the Boolean operations are done behind the scenes or default to specific Boolean "operators." However, searchers with more complex needs should verse themselves in the basic Boolean concepts to better use the search screens and to help themselves find appropriate information more quickly.


Which Boolean Operators Does AgeLine Use?

AgeLine uses the Boolean operators AND, OR, NOT, and NEAR. The search engine automatically performs Boolean NEAR between words in the Basic and Advanced Search screen boxes and in the Title, Author, and Any Word Search boxes on the Multiple-Option Search screen. In all of the AgeLine search boxes on all of the search screens, a semicolon between words or phrases performs a Boolean OR. Radio buttons between search boxes on the Advanced Subject Search and Advanced Search screens default to Boolean AND but may be changed to perform Boolean OR or NOT. On the Multiple-Option Search screen, a Boolean AND is performed automatically if search queries are entered in more than one search box.


What Does Each Boolean Operator Do?

OR

OR means "either one or the other, or both." If you search diabetes OR cancer using the Basic or Advanced Search screens, the search engine will deliver all the records that have either the word diabetes or the word cancer somewhere in the abstract, title, journal title, author names, or subject keywords. It will also retrieve those that have both diabetes and cancer information. A Boolean OR search is almost always broader (retrieves more records) than a Boolean AND search between the same two terms. In the search boxes, a semicolon between words or phrases performs the Boolean OR operation. Boolean OR (in the form of a semicolon) is automatically added between two or more items pasted in a search box from one of the BROWSE indexes of the Title, Journal Title, Author, and Subject Search boxes.

AND

AND means "all are required." Boolean AND requires that all of the terms searched must be present in one record for that record to be retrieved. If you search for diabetes AND cancer, a record will be retrieved only if it has both the word diabetes and the word cancer. Records with information on both diseases are fewer than records with information on either one or the other disease, so you will retrieve fewer records. AND is the default Boolean operator between search boxes on the Advanced Subject Search, Advanced Search, and Multiple-Option Search screens. On the Advanced Subject Search and Advanced Search screens, click on the radio buttons between search boxes to change from AND to OR or NOT.

NOT

NOT means "but not." Boolean NOT asks the search engine to exclude selected words or phrases from a search result. Boolean NOT should be used cautiously--only after a search brings up too many records and one can appropriately exclude particular words or concepts by using NOT. For example, AgeLine has hundreds of records on Medicare and hundreds on Medicaid. Some records describe documents that focus on both programs. If you are searching for information on Medicaid, you may want to use the NOT operator to exclude Medicare. However, you should be aware that you are cutting out any record that has both Medicare and Medicaid information, because you are asking the search engine to retrieve only those that address Medicaid and NOT those that address Medicare.

NEAR

NEAR in AgeLine means "within 5 words, either direction." Boolean NEAR locates words that are within 5 words of each other in each record. AgeLine automatically uses the Boolean NEAR between words in the AgeLine Basic and Advanced Search boxes and in all but the Journal Title and Subject boxes of the Multiple-Option Search. For example, if you input florida assisted living into the search box on the Basic Search screen, the search query translates it to the following:

florida within 5 words of assisted within 5 words of living


This query will retrieve such phrases as Florida assisted living, assisted living in Florida, and assisted living and retirement facilities in Florida. However, it will not retrieve a record with the phrase assisted living facilities in Georgia, Alabama, South Carolina, and Florida, because in that phrase Florida is more than 5 words away from living. To be sure of getting a record with this phrase, use the Advanced Search screen and type assisted living in the first search box and Florida in the second search box. This will retrieve all records with assisted NEAR living that also have Florida somewhere in the record.


What Is Truncation?

To "truncate" means to shorten. AgeLine's web search engine uses truncation in three of the four search screens.

Basic Search Box

 Automatically truncates each search word after the 7th
character. This often gives several forms of a word (including
singular and plural) without the searcher having to think about
the various forms. Example: If the searcher types in
consumer expenditures, the search engine reads it as
consume* expendi*.

Multiple-Option
Search Boxes
Title Truncation at the end of every word that is 5 characters or longer
(done automatically for searcher).
Example: consumer* expenditures*
      or
Searcher can truncate, depending on need.
Example: consum expen
Journal Title No truncation (neither automatic nor by searcher)
Author No truncation (neither automatic nor by searcher)
Subject No truncation (neither automatic nor by searcher)
Any Word Truncation at the end of every word that is 5 characters or longer
(done automatically for searcher).
Example: consumer* expenditures*
      or
Searcher can truncate, depending on need.
Example: consum expen

Advanced Search
Box

 Truncation at the end of every word that is 5 characters or longer
(done automatically for searcher).
Example: consumer* expenditures*
      or
Searcher can truncate, depending on need.
Example: consum expen

Advanced Subject
Search Box

 No truncation (neither automatic nor by searcher)


Note: Use the Advanced, Advanced Subject, or Multiple-Options Search screen if you want to avoid forced truncation after the 7th character.


Why Are the Boolean Operators AND and OR Sometimes Confusing?

In the English language we are used to thinking of and and or somewhat differently than is required by Boolean logic. If you say, "I would like a Golden Retriever and a Labrador Retriever," you will get two dogs; whereas if you say, "I would like either a Golden Retriever or a Labrador Retriever," you will get only one dog.

However, Boolean logic is really asking something else, as the examples below illustrate:

Boolean OR

"Out of all the dogs in the animal shelter, I need all of those that are either Golden Retrievers or Labrador Retrievers, or a cross between the two."

Boolean AND

"Out of all the dogs in the animal shelter, I need only those that are a cross between a Golden Retriever and a Labrador Retriever."

For more information and examples using Boolean operators in searching, see the Search Help topics offering tips on the four search screens.


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