Boolean Operators in Search Phrases
What are Boolean Operators
are Search operators, which are words and symbols that provide
instructions for a search engine, on how to direct a search. For example,
search operators can tell the search engine to exclude certain webpages, or to
include webpages with specific phrases.
Search operators can be manually inserted directly
into a search phrase, which I will discuss in this section. However, they can
also be generated with the advanced search functions that are available in many
search engines, which I will discuss in the next chapter.
From a technical perspective, Boolean operators,
resemble certain mathematical concepts from set theory. However, the symbols used in set theory are
different from the words and symbols used with search engines, but many of the
concepts are the same. For example, when you create a search phrase you are
essentially defining a set of webpages,
which have the information you need. Boolean operators are used to define the
set of webpages more precisely.
A domain that has a number of webpages and/or
several subdomains can also be defined as a set, such as www.TechForText.com. Sometimes web-based searches involve defining a
subset. A subset of the above can be defined as
site:TechForText.com Trigonometry This subset has 36 entries, with the word
trigonometry, based on a Google search, performed on 3/5/2014. Left click on the blue
underlined words to see the search results, from Google.
If you want more information about set theory and Web searches see the following: Using a Search Engine -- Set Theory for Beginners, URL: http://goo.gl/ndRDtW
The Practical Application of Search
What are the Most Useful Search Operators?
I have found that the most useful search operators are
quotation marks, “
”, OR, AND, the asterisk *, and site:. I will explain how
to use these operators under the following subheadings, with examples.
IMPORTANT NOTE: Most of the examples in this section involve search
phrases, with specific operators. I tested these phrases with Google, and the
number of search results I obtained is indicated for each example. You can repeat these
searches by left clicking on the blue underlined text next to each example. The number of search results you
get, will probably not be the same as the number I obtained, when I tested
these phrases. This is because Google constantly updates its databases.
The Use of Quotation Marks In Search Phrases
I have found the following technique very useful, and
it involves creating search phrases with quotation marks. Specifically, quotation
marks on a search phrase will increase the selectivity of the search results.
That is, with this technique you can increase the focus of your search, and
eliminate unwanted search results. However, it can be somewhat of a challenge
to figure out precisely where to place the quotation marks on a specific search
phrase. The following explanations involve hyperlinks to Google search
pages. To activate a hyperlink left click on the blue underlined text. If a
link fails access www.Google.com directly, and entered the indicated search phrase
into the Google’s search box.
To explain how to increase the effectiveness of a
search, with quotation marks, I will use Google, with the following search
studies of deep-sea animals in the Atlantic Ocean. The
results I obtained with various arrangements of quotation marks are presented
Without quotation marks I obtained approximately 1,900,000
quotation marks on a phrase, the search results can include any web-based
document that has all the words in the search phrase regardless of their
When the Entire phrase was placed in quotation marks,
such as: “Scientific
studies of deep-sea animals in the Atlantic Ocean”
Google indicated: 1,350,000 results. This was followed by: No results found for “Scientific studies of deep-sea animals in
the Atlantic Ocean”. Quotation
marks on a long search phrase can make the search excessively selective, which
can result in no search results.
When I used two sets of quotation marks I obtained
approximately 506,000 results. “Scientific studies” of deep-sea animals in the “Atlantic Ocean”
When I use three sets of quotation
marks I obtained approximately 964 results. “Scientific studies” of “deep-sea animals” in the “Atlantic Ocean” This
last example is the ideal, with this search phrase.
The idea here is to place quotation marks on two
or more words that are important for your search. With the above example, the
important word combinations are Scientific
animals, and Atlantic
Do NOT place
words that are unimportant for your search in quotation marks. With
the search phrase used above as an example, the unimportant words are of, in,
Thus, with this example, all of the following are INCORRECT:
“Scientific studies of” “deep-sea
animals in the” “Atlantic Ocean”
“Scientific studies of deep-sea animals” “in the Atlantic Ocean”
“Scientific studies of” “deep-sea
animals in” “the Atlantic Ocean”
To develop insight and skills using quotation
marks carry out your own experiments with various search phrases, and quotation
marks. Keep in mind that web searching is a trial and error process,
especially when quotation marks are used.
The Use of OR
In Search Phrases
The use of a capitalized OR in a search phrase is
useful in the situations described below. When using this operator, it might
also be necessary to use quotation marks. You must properly place the
quotation marks, and the OR, on the words comprising your search phrase. This
will be explained in the following paragraphs, with examples.
is useful when the same concept might be described with different words, such
lions” OR “white lions”
This search phrase worked well with Google, and it
produced approximately 808,000 results.
I repeated this search with Google Images (www.Google.com/imghp). This resulted in a search page with photographs of
dozens of white lions.
is possible to get similar results as the above, by conducting two searches,
one with “albino
lions” and the other with “white lions”, without using OR. With the search phrase “albino lions”
I obtained approximately 17,600 results. With the search phrase “white lions” I
obtained approximately 792,000
results. This totals to 809,600, which is not much
different than the 808,000 results
I obtained with the search phrase: “albino lions” OR “white lions”
OR can be useful, in a search phrase, when you want to find
information that relates to two or more localities. For example, with the
following search the localities are Atlantic and Indian oceans: “Scientific studies ” of “deep-sea
animals” in the “Atlantic Ocean”
OR “Indian Ocean”.
Google I obtained 1,120 results.
some cases, you might get more results by carrying out two separate searches,
without the OR. When I conducted one search for the “Atlantic
and another for the “Indian Ocean”, I obtained a total of 1657 results, from the two
searches. This is more than I obtained with OR, with one
search. This involved the following search phrases:
“Scientific studies ”
of “deep-sea animals” in the “Atlantic Ocean” With Google I obtained 966 results.
“Scientific studies” of “deep-sea animals” in the “Indian Ocean” With Google I obtained 691 results.
Use of AND in Search
If you want to find web-based documents that contain two or more
concepts, words, or items on a page, use the AND. For example, with the search
phrase cats AND dogs, webpages that have only the
word cats or only the word dogs, will NOT appear in the search results. Only webpages that have
both of the words: cats and dogs will appear in the search results. When
I tested the search phrase cats AND dogs with Google
I obtained approximately 198,000,000 results. I repeated this test with Google Images (at www.Google.com/imghp), and a webpage was displayed with dozens of photographs,
which had at least one cat and one dog in most of the pictures.
Using the Asterisk * for Unknowns in
When you are not
certain of the correct words for an effective search phrase, you can use
asterisks, which are symbolized as
The examples presented below will clarify the utility of this search operator.
When the following search phrase was used with Google
without an asterisk *, it resulted in 117,000 results. “Techniques for” “improving study skills”.
of the results, with the above search phrase, appear to be relevant. However, replacing the word techniques with an asterisk * might be useful in this
case. With the above search phrase, the websites that do not have the word techniques, will not be displayed on the search page. Keep
in mind, that many words are approximately equivalent to techniques, in terms of search criteria. Examples
are method, strategies, tips, or even websites, books,
or courses. By using an asterisk *, instead of the word: technique, there should be MORE results, as indicated below:
“* for” “improving study skills” The Google search page indicated 1,420,000 results.
repeated the above search, without
the asterisk * and without
the word technique. I did this to determine if the asterisk
was really doing anything.
“ for” “improving study skills” Google search page indicated only 251,000 results.
This is much less than the 1,420,000 with the asterisk *.
Search Phrases with Site: to Focus on a Specific
When you want to search for information from a specific website
domain, use the word site with a colon, with Google. For example, if I wanted
to search www.TechForText.com for information on calculus, I
would create the following:
site:TechForText.com calculus With this search phrase, Google’s
search page indicated 56 results, from the domain www.TechForText.com
There are Many Search Operators
In the preceding paragraphs, I
presented only five search operators. However, there are many other search operators, which are
useful with Google, and other search engines. If you are interested in these
operators and related information, see the websites listed below:
Words on website: GoogleGuide
Using Search Operators, URL
Words on website: Search
Words on website: Search Tools - Advanced Features URL is
Words on website: Basic
Search Tips and Advanced Boolean Explained URL is http://goo.gl/ecavR
on website: Search
Words on website: Guides
— Using Search Operators in Justis, URL is www.justis.com/support/guide-operators-jcom.aspx
Words on website: Bing
Help Home > Advanced search keywords URL is
From Other Authors: Additional
and Supporting Information, and Alternative Perspectives, for Chapter 2
you want more information, alternative perspectives or explanations, see the
following websites and videos from other authors. To access this material left
click on the blue links, or the URLs presented below.
a link fails, enter the indicated search
phrase or the *words that are
displayed from the website, into the search engine presented on the
left of each entry. *Note the words from the website are indicated with Words on
you examine the following entries all of the above will be clarified.
from Other Authors to Supplement Chapter 2
www.Google.com Search phrase: "advanced search techniques" This is a Google search page, which
indicates 325,000,000 results.
www.Google.com Words on website: IBM Advanced search techniques URL is http://goo.gl/4nUd08
www.Google.com Words on website: Boolean
operators and truncation URL is http://libguides.tru.ca/content.php?pid=83262
on website: Advanced
Tips and Techniques URL is www.searchingspot.com/techniques.htm
www.Google.com Words on website: Search
operators URL is https://support.google.com/websearch/answer/136861?hl=en
www.Google.com Words on website: INTRODUCTION
TO LOGIC USED IN ELECTRONIC SEARCHING Boolean Logic Boolean Operators URL is www.exploratorium.edu/lc/search/boolean.html
www.Google.com Words on website: Google Algorithm and Axiomatic Set Theory, URL
www.Google.com Search phrase: "Boolean operators” and “Web searching" This is a
Google search page, which indicates 6,460 results.
www.Google.com Words on website: Basic Search Tips and Advanced Boolean Explained URL
www.Google.com Words on website: Advanced
Web Searching URL is www.learnthenet.com/how-to/advanced-web-search
www.Google.com Words on website: Using
a Search Engine, URL is www.askscott.com/sec2.html
www.Google.com Words on website: Web
on website: Google Search: The Asterisk Wildcard and Punctuation URL
Videos from Other Authors, to Supplement Chapter 2
When you left click on a link for a video, a webpage will open, and the video will
start automatically in most cases. The webpage that opens with the video will
usually have 10 or more RELEVANT
videos. If the video does not start automatically, and the webpage opens, left
click on the link provided by the author of the video. This link is usually in
the center of the screen.
www.Video.Google.com Search phrase: "advanced search" This is a Google
video search page, which indicates results 163,000,000.
www.Video.Google.com Words on website: Advanced
www.Video.Google.com Words on website: EBSCOhost
Advanced Searching, URL is http://youtu.be/JT-yMu6gvVM
www.Video.Google.com Words on website: Google
Advanced Search Tips, URL is http://youtu.be/cJpnu3D9f_Q
Words on website: CINAHL Databases -
Advanced Searching Tutorial, URL is http://youtu.be/0QjtxVVsKqA
www.Video.Google.com Search phrase: “Boolean operators” and “Web searching” This is a Google
video search page, which indicates 92 results.
www.Video.Google.com Words on website: Effective Web Searching
Library Database Searching Techniques URL
www.Video.Google.com Words on website: Searching
The Internet - A Primer URL is http://youtu.be/FtzDWePs47k
www.Video.Google.com Words on website: Library
Database Searching Techniques URL is http://youtu.be/1By32B1MTLg
Words on website: How
to be a Google Expert, URL