What are keywords?
Keywords are simply the words that you put in any search box.
Where do I get my keywords?
If your professor has you write your research topic out as either a thesis statement or a research question, that is a good starting point. Look for the major nouns in the sentence. Verbs and little words like pronouns, particles, and prepositions (the, a, they, to, on, of, it, about, etc.) are used so much that they don't add anything to your search. The sentence below shows all those little words removed.
So from the sentence above, I would enter just the nouns hydraulic fracturing, contamination, and water.
What if I don't get great results?
The English language is very large and is full of synonyms and words/phrases that represent similar or overlapping concepts. For example, instead of the word teens, an author might use any of the following: teenagers, adolescents, young adults, or youth.
From the example above:
hydraulic fracturing could also be called fracking, and
contamination could be replaced with pollution.
Even changing a single word can have a great affect on your search results. The Keywords video below shows this in action.