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*Finding Sources*

Identify Key Terms


Look at your working thesis statement, or the topic of your paper.  What are the major terms that you find?  These are the key terms, or keywords, that you will want to use to begin creating your search.


Something to keep in mind when creating your search terms is synonyms, or words that mean the same thing.  It may be that the specific term (or terms) you have chosen has synonyms.  Make a list of synonyms for each of your keywords.  This will give you a variety of terms you can use in your search if your original words don't get the results you want or need.


Your key term(s) may have homonyms - words that are spelled the same that have a different meaning.  Consider the word bass.  Do you think of a fish, or a stringed instrument, or the low register in music?  If this is one of your search terms, you may have to use some special tricks to get the correct results.  But don't worry!  We are going to look at how to deal with synonyms and homonyms right now.

Choosing Your Keywords

McMaster Libraries. How Library Stuff Works: How to Choose Keywords. YouTube. Creative Commons Attribution license (reuse allowed)


Boolean Operators

So, what do you do when your search term has synonyms or is a homonym, or you get way too many unrelated results when you do your search?  You use Boolean Operators!

Don't let the term throw you off!  This method uses the words AND, OR, & NOT to help define your search.  When you do a search on Google, it ignores those words and looks for pages that have all, some, or one of your search terms.  That's why you can get so many results, with a large number of them having nothing to do with what you want.  However, when you use these words in a database search, it will narrow or widen your search. 

Let's take a look at what each one does.


Boolean Operators. AND: Only results that contain both keywords.  OR: Results containing keyword A OR B.  NOT: Results containing keyword A, excluding any with keyword B.

Cecelia Vetter, Diagram Explaining Boolean OperatorsCC BY-SA 4.0, via Wikimedia Commons



It might seem like AND would give you more results.  But, it actually narrows your search down by looking for items that contain BOTH words, instead of just one.  This word is good to use when you get lots of results that aren't really related to what you want.  You will need to choose another term that will narrow the results down to your specific topic.

For example, if you want to find articles that discuss pet ownership of multiple types of animals at one time, you might want to use cats AND dogs for articles about people who have both. 

You can use AND to deal with homonyms by choosing a term that would specify your usage of the word.  For example, bass AND fishing  or bass AND orchestra will lead to significantly different results.



OR is almost the opposite of AND.  OR gives you more results by looking for either of the terms entered.  Use OR when you want to include synonyms in your search. 

Following our example from AND, say you now want to find pet ownership articles, but you don't really care which type they have, just that they have either cats OR dogs.



NOT acts like AND by narrowing your results.  You can use it to exclude terms that you do not want.  

Using our pet example, you could search dogs NOT cats to get results that do not include cat owners.

You can use this to remove results for homonyms by using NOT with a term that would indicate the other usage of your term.  For example, bass NOT fish, which will provide results such as the orchestral instrument, or the low end of the vocal range.




Check out the following video for examples of using Boolean Operators.  

McMaster Libraries. How Library Stuff Works: Boolean Operators (AND OR NOT). YouTubeCreative Commons Attribution license (reuse allowed).



Subject Headings

Once you have started your search, you can also make use of subjects and subject headings within a database.  You can often find these in a list next to your search results, or included in information about a source when you view it.  Clicking on a hyperlinked subject will get you a list of all of the articles that also have that subject.  You can also use the subjects to choose keywords when refining your original search.

A circle marks the location of Subjects on a page of results in an EBSCO database search.  It is on the left side below limits and source types.

Location of Subjects in an EBSCO search results list.  You may need to click on an arrow next to Subject to display the list.  Selecting a subject here narrows your current results to articles with that subject.  If you click on Show More, you get a larger list, and you can select multiple subjects.


A circle marks the location of Subjects in an EBSCO article.  It is found in the middle of the page below the title of the article.

Location of Subjects in an EBSCO article.  Clicking on a subject in this list will retrieve all articles in the database with that term listed as a subject.


A circle marks the location of subjects in the results of a Gale database search.  The appear to the top right of the list of results.

Location of subjects in the results of a Gale database search.  Clicking on a subject here will narrow your current results to only those articles with the selected subject.


A circle marks the location of subjects in an article in a Gale database.  They are located to the right of the article, below More Like These.

Location of subjects in an article in a Gale database.  Clicking on a subject here will retrieve all articles in the database with the same subject.