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Learn How to Research

Breaking Down the Question 

Before you start searching you will want to break down your question into keywords and identify some possible synonyms or like-terms. This helps the academic search engine find more specific results. Not all of your keywords will have like terms. 

The question: "Why do people who are exposed to air pollution from oil refineries suffer from more respiratory diseases?"

Keywords and Like-Terms: 

Air Pollution -> smog, toxic, chemicals, airborne pollutants 

Oil Refineries 

Respiratory Diseases -> asthma, air-quality, shortness of breath 

Now that we have identified our keywords and like-terms we can connect them together using the operators below. 

Boolean Operators 

Boolean operators are the words that we use to connect our keywords and like-terms together. There are three Boolean operators:

AND:  Looks for both terms in the results (use to connect keywords)

OR:  Looks for one or the other in the results (use to connect like-terms) 

NOT: Looks for one term but not the other in the results (use to exclude a term)  

You do not have to capitalize them in all databases, but it is a good habit to get into because some databases require it.


"Boolean Operators" by rikhei is licensed under CC BY-NC-SA 2.0

Other Operators 


Truncation accounts for different endings on a root word. By placing an asterisk (*) on a root word you can include all possible endings. 

e.g. Canad* searches for Canada, Canadian, and Canadians 


Using a wildcard allows you to replace a letter inside of a word. This is useful if you are searching a word that has different spellings internationally. It is also useful if you are doing genealogical work and looking for different spellings of last names. Note that not all databases use wildcards and some databases use different symbols. Check the "help" option in your database to make sure. 

e.g. Ols?n searches for Olson, Olsen, Olsan 

Phrase Search

When you have two or more words that need to stay together, put them in quotation marks. This tells the search to look for the phrase, not the individual wordsThis is also useful if you are looking for a title. 

e.g. "central nervous system" 

Search Strings 

Now that we have identified our keywords and like-terms, we can connect them using the above operators to create a search string which is what we will put into the search bar of our academic search engine. 


(("air pollution" OR smog OR toxic OR chemical* OR "air-borne pollutants*") AND 

("oil refiner*") AND 

("respiratory disease*" OR asthma OR air-quality))

The parentheses that you see used in this search string are called nesting and they are used to keep like-terms together and separate from other keywords. 

If you use an advanced search (seen below) you do not need the parentheses, instead, separate your terms using the boxes provided.