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At this point in your search process, you are moving from merely identifying main concepts and similar search terms to developing more complicated search statements that can do more precise searching. Unlike natural language searching, all of the techniques discussed below are considered advanced search techniques.

NOTE: Before we discuss the following search techniques, it is useful to know that, in general, capitalization and punctuation are not recognized in search engines, except for the instances discussed below. 

Use Quotation Marks for Phrases

Put quotation marks around any phrases among your terms so that the phrase is what’s searched for, rather than the separate words. “Common cold” instead of common cold is a good example. Without those quotation marks, just think how many results a search engine would return that has nothing to do with your intentions for the search you are doing. It’s also worth it to note that the closer two terms appear near each other, the more impact it has on the meaning. These two words appearing next to each other in this order create the unique meaning for the phrase. Putting quotation marks around a phrase (two words or more) signals to the search engine that you must find these terms in the results that get returned to you.

Quotation marks around the phrase common cold.
Putting a phrase in quotes returns results containing that phrase,
and not the results for the individual words.

Using quotes around your phrase is also a tool for searching for known items, meaning, if you are searching for a specific title, say, “The Importance of Being Earnest”, you will only receive instances where the previous title/phrase is found. You are also telling the search engine in this case that you want the stop word “The” in the results of your search. (Otherwise, The and for that matter, of, would not be searched without the quotation marks around the title/phrase.)

The use of quotation marks is a very powerful search command, and is usually available in open web search engines and database searching. (The only thing to keep in mind here is that a different symbol might be used besides the quotation marks, “”, but this is rare. The search tool’s Help Page will tell you exactly which symbol a particular tool uses for this type of searching.

Use Wildcard and Truncation Symbols to Broaden

Consider whether using wild card or truncating symbols would help find variations of a word. For instance, the wildcard symbol in wom?n finds woman, women and womyn, and the truncating symbol in mathematic* finds mathematics, mathematically, mathematical, mathematician, etc.

Asterisks (*) match any number of characters that fit the rest of the pattern, and the question mark (?) matches a single character within a pattern.
Using wildcard characters allows you to find variations of a word.

Wildcards are used when you want to find a variation in spelling as in the example above (where the use of either variation does not change the meaning of the word); truncation is used when you want to find a root term with its various endings as in the example of mathemat* above.

Again, remember that what a particular search tool uses to represent a wildcard or truncation search will depend on the tool itself. Using a wild card  or truncation symbol allows for a more efficient search. Instead of searching for each of a word’s variations one at a time or by using a series of OR commands between each and every variation of a word, you are telling the search engine in language it understands to do the heavy lifting for you. See the Help Page of a particular tool for guidance.

Consider AND, OR, NOT

You can often do more precise searching by combining search terms by using the words AND, OR, and NOT.  These are known as Boolean Operators. (To distinguish operators/commands from stop words in a search engine, operators/commands are capitalized.) Generally, using these operators narrows your search, making it more precise.

Venn diagrams showing how searches using AND and NOT narrow search results, while those using OR expand search results.
The Boolean operators AND, OR, and NOT exclude or include
subsets of sources.

AND – If the main idea contains two or more separate and independent ideas, you’ll want to use AND to combine those terms in your search statement. To look for information about spiders as signs of climate change, you’ll want to have both terms in the search and perform an AND search like this: spiders AND “climate change“. (Notice the use of quotation marks in the above example. In many instances, the AND operator is already assumed in search engines like Google and Bing, so you don’t have to enter AND as an operator in these instances. If you want to search using a different operator in these search engines, you must explicitly include these operators OR or NOT. (In Google, the use of a minus sign, -, is used in place of the use of NOT.) For example, stars NOT celebrities or starscelebrities.

OR – If the main idea has several synonyms and you want to broaden your search, use OR between similar terms. Most search tools search for all terms (AND) by default; however, OR is not implied in a search box, so you need to use the term OR between terms to find a term and the synonyms you want found. For instance, in the  example of Latino small business growth, you should include Hispanic as a similar term because you want results about the concept of Latino OR Hispanic small business growth, as these two terms are often used interchangeably in the literature and there is no telling when one author might prefer one term over its synonym.

NOT – If the main idea has a common use you want to exclude, use NOT to exclude that word. For example, if we were looking for information about illegal drug use but not prescription drug use, you would use the NOT operator to tell the search engine to exclude illegal drug use involving prescription drugs. This is commonly done with NOT or the use of the minus (-) sign. In Google, to exclude a word use – word with no space between the – and the word you want to exclude. If you put a space in there, Google will not exclude the word, as in stars -celebrities. (When using some search tools, you may have to use AND NOT before the word to exclude it.)

For example, how would you interpret this search statement given the above information:

“illegal drug use” OR “illicit drug use” NOT “prescription drugs”

In other words, explain the results you would expect to retrieve from the above search statement.

Using Parentheses with Multiple Operators

When a search requires multiple Boolean operators (AND, OR, NOT, or their symbols), you must use parentheses to group the appropriate terms and quotation marks with each Boolean operator. The resulting statements connect terms, remove terms, and organize search terms in ways that result in complex and precise searching.

The use of parentheses may remind you of the mathematical statements written in math courses. The reason parentheses are necessary in searching is that search tools, including Google, generally perform their operations from the left to right of a search statement. If you are using multiple Boolean operators, then the way to make sure that the search is done as a whole statement requires that you use parentheses to combine the sets in your statement.

Use parentheses only when you are using multiple Boolean operators in a search statement.

Parenthesis are used with Boolean operators to combine terms
for complex searches.

Being skillful at this task of envisioning the effects Boolean operators have on a search can help you troubleshoot your own search statements when they aren’t turning up what you expected.

Example: “United States” AND (immigration or emigration)

Can you tell that the searcher wants to find information about the United States’ immigration or emigration?

The searcher will find more with this arrangement than would turn up if the statement had been “United States” immigration emigration. That’s because the latter arrangement without parentheses would find only information that was about both United States immigration and emigration, instead of either.

Example: (cats OR dogs) AND (treatment OR therapy)

Can you tell that the searcher wants to find information about either treatment or therapy for either cats or dogs?

That’s a different search from what the searcher would have gotten if this statement had been used: cats dogs treatment therapy. Anything found with the latter statement without parentheses would have had to be about both— not just either—therapy and treatment for both—not just either—cats and dogs. So the latter statement would have turned up much fewer results than the search statement above.

 


Practice with Search

Take some time to practice searching precisely – start by identifying main concepts, then listing related and alternative terms (with the help of wildcard and truncation symbols), and finally constructing search statements using quotation marks around phrases, and/or parentheses when using multiple operators.

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Choosing & Using Sources: A Guide to Academic Research Copyright © 2015 by Teaching & Learning, Ohio State University Libraries is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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