Boolean operators what they are for, list and examples

1599
Egbert Haynes

The boolean operators They are components of an algebraic logical system formulated by George Boole, a 19th century English mathematician, that tell search engines what concepts they want to include or exclude in the results.

Computers can contain a great deal of information. To find the correct information in databases and websites, you must understand how to build efficient searches using Boolean logic..

Source: pixabay.com

In a Boolean search, the Boolean operators AND, OR, and NOT combine keywords to narrow or broaden a search. They are basically algebraic operations that involve variables with two values, such as Value 1 AND Value 2, Value 1 OR Value 2, Value 1 and NOT Value 2.

Generating Boolean searches is a skill that must be known in order to obtain meaningful search results from a wide range of software. Therefore, it should be developed if you want to be successful..

Although long Boolean search strings may seem complicated to create because they are fuzzy and tangled, this is not to be feared, because they are not really..

Article index

  • 1 What are Boolean operators for?
    • 1.1 Efficient search for terms
  • 2 The most common Boolean operators
    • 2.1 AND
    • 2.2 OR
    • 2.3 NOT
    • 2.4 Quotes
    • 2.5 Nesting
  • 3 Examples of the use of Boolean operators
    • 3.1 When any of the options works
    • 3.2 When several terms need to be found together
    • 3.3 When you don't want to find something
  • 4 References

What are Boolean operators for?

Boolean search is a way of establishing a search using a set of keywords and the three main Boolean operators (AND, OR and NOT), to obtain more precise and more relevant results in searches..

The first thing to appreciate in the Boolean system is that there are only five elements of syntax to understand. These are: AND, OR, NOT, (), "".

By using them appropriately, together with the keywords being considered, a wide range of search operations can be created.

There is no limit to the repetition with which any of these elements can be used in a search, so very specific search strings can be created, saving a lot of time in filtering the results.

Efficient search for terms

Databases and search engines are often very accurate. When words are typed into the search box in a database, the database will strictly search for those words.

If the documents in the database use different words to clarify the topic, they may not be found. On the other hand, running searches for every possible keyword would be time consuming and inefficient, as well as not providing the level of specificity that might be required..

The use of the Boolean operators or search connectors AND, OR and NOT allows you to combine keywords in order to generate more meaningful searches. They are a central component for an efficient search strategy.

The most common Boolean operators

The most common Boolean operators are AND, OR, and NOT. Can be used to get more precise search results.

AND

When this Boolean operator connects the terms, only those entries that contain all those connected search terms will be selected. Can be used to narrow a search.

Therefore, AND has to be added to get results that contain both words (shaded area of ​​the diagram). This will not guarantee that the words appear next to each other, only that both words will be present in the results, such as "electoral vote with electronic device".

OR

When terms are connected by this Boolean operator, entries that contain any of these search terms, either together or separately, will be selected. Can be used to broaden a search.

OR is also used to request an alternative, for example “electronic OR manual vote”. Most search engines will interpret this as "vote AND (electronic manual OR)".

NOT

When terms are connected by this Boolean operator, entries that contain a particular term are excluded. Can be used to limit a search or eliminate false hits.

NOT tells a search engine what to ignore. The "vote NOT manual" query will return results that contain the word vote, but not the word manual. Some search engines use a minus sign in front of the word instead of NO, for example, -manual.

Quotation marks

Although it is not a Boolean operator, quotes can be used for more precise results.

In general, search engines treat the query "electronic vote" as electronic AND vote, which means that the results should contain both words together, such as "electronic vote for elections". By doing this, the result "electoral vote with electronic device" will not be returned..

Nesting

When more than one type of Boolean operator appears in the same search operation, parentheses () are used to confine the terms to be combined with the operator. For example: (infant OR baby) AND (drugs OR alcohol) AND abuse

Examples of using Boolean operators

Suppose you are writing an article about the influence of social networks on the communication skills of adolescents.

When any of the options work

There are many different ways of calling the concept "social networks". The authors of the resources to search could call it a social network or social networks, or there may be some valuable resource that only talks about Facebook as an example of social networks, without using the words “social networks”.

The Boolean OR operator is used when looking for different options, where any of them will do. For example: "social networks" OR "social network" OR Facebook.

When several terms need to be found together

If you only search for topics related to social networks, you will surely find many documents. However, those resources could talk about almost anything, such as social media design, using social media as a marketing tool, etc..

Therefore, if in this case you want to find documents related to social networks and communication, you should search where both terms appear. The Boolean AND operator is used when searching for several terms together. It would be: "social networks" AND communication.

When you don't want to find something

Sometimes the combination of keywords being used will retrieve resources that are not wanted.

For example, searching for documents on the terms "social media" and "communication" could find resources on the use of social media in mass communication or marketing..

However, neither of these terms is relevant to the topic of adolescent communication skills. When you need to exclude terms from your search, you use the Boolean NOT operator. For this case it would be: communication NOT marketing.

References

  1. University of Maryland (2020). Boolean Operators: AND, OR, and NOT. Taken from: myelms.umd.edu.
  2. Social Talent (2020). The Beginner's Guide to Boolean Search Terms. Taken from: socialtalent.com.
  3. BBC (2020). Searching information on computers. Taken from: bbc.co.uk.
  4. Virginia Highlands Community College (2020). Boolean Operators - A Brief Explanation. Taken from: vhcc.edu.
  5. University of Toronto Libraries (2020). What are Boolean operators? How can I use them to improve my searches? Taken from: library.utoronto.ca.

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