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Boolean Operators - Part II
Last week we looked at the use of Boolean operators for searching on the Internet and in EBSCO, which you should be using in the National Library when you’re working on SBA’s. Below, you’ll find a review of the logical operators. We will introduce positional operators and truncation. Boolean operators help you to zoom in on the sites you need for research.
The Logical Operators:
Here are the most common operators for a Boolean search.
AND - Each record you pull up must contain all search terms that you type. This means that (AND tends to narrow a search). If you type in French dessert cookbooks AND Ina Garten AND will look for all of those terms.
OR - Each record must contain at least one search term. If you type in French dessert cookbooks OR Ina Garten, you get one of the other. (In other words OR tends to broaden a search).
A third logical operator is the NOT operator. This is not highly recommended in high school because it is difficult to navigate your way through such searches. Sometimes it is helpful. The NOT operator eliminates possibilities, but it can sometimes eliminate information you want or need. For instance, I might want to do a research paper on Diseases of the cocoa plant, but I don’t want Witch’s Broom, I could do a search like this: Cocoa AND disease NOT Witch’s Broom. That search would eliminate witch’s broom, but there might be some useful information about cocoa diseases in those articles about Witch’s Broom.
You can also see how useful a Boolean search is, in this case, if you consider you might be doing a research paper on Cocoa research, but you don’t know if it’s spelled Witch’s broom OR Witches broom. You could take care of that by searching for both terms, getting the correct spelling and then narrowing your term.
The Positional Operators:
Boolean positional operators allow you to retrieve only those records that appear in the order you put them. This helps to narrow a search as well. Here are two useful positional operators to use:
Adj – Here, search terms must be adjacent (side by side), in the same order. This would help for searching Witch’s broom so that you don’t pick up Internet articles that contain the term Witch’s or broom.
Same - Here, you search for terms that might not be in the same order. This is particularly helpful if you’re searching for a general term that could be expressed in many different ways.
Examples of Search Expressions Using Positional Operators:
drug SAME abuse <<Retrieves drug abuse, abuse of drugs, abusing drugs, abused drugs
Witch’s ADJ broom <<Retrieves Witch’s broom only
TRUNCATION - Abbreviations for a Boolean search
Once you know what symbols can be used for truncation, you can retrieve information in which you don’t necessarily know the exact word or spelling. Truncation allows you to pull up all the letters before the sign which could be a question mark.
Examples of Search Expressions Using Truncation
colo? <<Retrieves color, colours, Colorado, colony, etc.
Math majors will love nesting. This allows you to build complex searches. You build relationships for nesting by using brackets just as you do in algebra.
Examples of Search
Expressions Using Logical Operators
(mothers OR parents ) AND discipline
(airport? OR airplane?) AND terror?
The first example will retrieve records in which the words mothers AND parents and discipline appear.
The second example is an even broader search. Here, the question mark will allow you to retrieve airport, airports, airplane, airplanes in records where the term(s) terror, terrorist, terrorize, terrorists, or terrorism appear in the same record.
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