It is very important to have a variety of keywords to search. This is because some terms will yield more results than others and/or results that are more relevant to your research paper topic. There is no one "correct" search word to use. Different keywords will give you more results:
We use filters because nobody has time to go through thousands upon thousands of results.
Use OR to expand with synonyms:
Birth control OR Contraceptives
If you don't use truncation, wildcards, and/or quotation marks, some databases will look for an exact match to the words you type, and you may miss some relevant materials.
Truncation (asterisk):
child*
Child* brings up child, children, childhood, and any other word that starts with the root "child." This works in most of the databases.
Wildcards (usually a question mark or exclamation point):
globali?ation and analysis
Globali?ation brings up items with the words globalization or globalisation.
Quotation Marks:
"Birth control" AND African American women AND United States