Post on 26-Dec-2015
BooleanLogic
… and other search strategies that work!
Using Boolean Logic and Other Techniques to
Enhance Search Statements
Because the Internet is so huge, searches will often provide too many results. When creating search statements you should take advantage of additional techniques to refine your search results.
Boolean Logic
Boolean logic, particularly the use of the Boolean operator AND, is the most important technique for limiting results in any database or search engine. These techniques include:
The principal Boolean operators are:
Boolean Operator
s
Use for Examples
AND + Use AND to get fewer search results
cake AND chocolate
OR Use OR to get more search results
adolescents OR teenagers
NOT - Use NOT to get fewer search results
media NOT radio
ANDRetrieves only records that contain
both words- Combine your key concepts using AND
NOTEliminates material you don’t want- Be careful not to get rid of stuff you
might actually need
ORRetrieves matches for either term, so you
get more records. Use with terms that have about the same meaning in your
search
NestingCombine AND and OR in a single search.
This technique divides your terms into units like an equation, by using parentheses.
Examples: •fruit AND (apple OR orange) •(fruit AND juice) AND apple •fruit AND (apple OR orange) AND juice •(fruit AND juice) AND (apple OR orange) •((fruit AND juice) AND (apple OR orange)) AND NOT banana
NOmedia AND politics OR election retrieves records that
match "media that also match politics" OR retrieves records that match "election."
YES media AND (politics OR election) retrieves records that match media that also match either politics OR
election.
Truncation and Wildcard
Truncation is a technique that enables a searcher to look for a word and any of its
possible endings. This is sometimes called using a "wildcard" as it usually enables the searcher to insert a symbol as a wild card at
the end of a word.
This symbol instructs the computer to look for the root of the word and all alternate word
endings or variations of a word and expands your search results
Use a symbol (like an asterisk * , !, or ?) at the end of a word to replace any number of letters
(truncation). Example: teen*
teen, teens, teenager, teenagers, teenaged
Use 1 or more symbols within a word to replace 1 or more letters (wildcard)
Example: wom?n women woman
Truncation and Wildcard
Use enough of a root word not to confuse the computer. Using opera*
to search for operations retrieves opera, operant, operable etc.
In most search engines, and in many databases, it is possible to search for a phrase, or two or more words appearing next to each other. The most common method for doing this is to surround the phrase with quotation marks.
Phrase Searching
For example:
A search for "acid rain" will look for those words in the database only when they
appear next to each other.
Other examples:
“May the force be with you”
“Hillary Clinton”
“presidential election 2008”
Use 6 to 8 key words in your query
More keywords chosen at the appropriate “level” will give you a smaller and more focused list of hits, greatly reducing the possible documents returned.
Examples: new, planet, planets, discover, solar, system.
Limiting and expanding a database search
Many databases will offer additional methods for limiting and refining search results. Some of these limiters may include:
–full text •you can search only for full text articles
–peer reviewed•you can search only for articles that are considered peer reviewed
–date range•you can search only for articles that have been published during a specific time period
Learning to use the database options
Use the help screens, and advanced search options
Remember that every database is different, offering different ways to create search statements or use controlled vocabulary. Each database will usually provide help screens to explain how to search effectively within that database.
TIP: Be aware that each database and search engine may use Boolean logic in a different way.
For example:In Yahoo and other search engines you can use the plus sign “+” as a Boolean “AND” or the “-” as a Boolean “NOT”.
Some search engines have pop down lists to help. In Yahoo, a pop down menu helps you to focus your search. In Google, you can use the advanced search feature.
EBSCOhostEBSCOhost allows you to select the
database that you want to search- so you can choose the one/ones that best suit your topic. These include:
• Academic Search Premier• Communications and Mass Media Complete• Health Source- Consumer Edition• Psychology and Behavioral Sciences Collection• Professional Development Collection• Religion and Philosophy Collection
Special EBSCOhost Features
Another feature of EBSCOhost that you might find valuable is the “Folder Option.” This option allows you to store items in a folder for a future session. To use this option, you will need to create an “account” first. Or you can just email them to yourself!
Want to practice some of these strategies?
Go to:
http://www-navigator.utah.edu/module3/fridge.swf