Change the terms you use in your search. Brainstorm about more specific terms. Use AND to combine search terms, for example women AND salary.
Start with a small number of keywords. Then add more terms or try different terms based on your results.
Add limiters (such as date and format).
Search by a field like "Title" or, Subject, or Abstract. Most databases by default search by keyword. For more refined results limit a search term to a more narrow search field.
Change the terms you use in your search. Sometimes by using a synonymous word, you'll get a very different results list.
Use fewer search terms. If you are searching for three or more search terms, try removing one. Always start with a small number of keywords, then add more terms or try different terms based on the results you get.
Remove limiters. Limiters (such as date and format) give you a more targeted results list, but sometimes limit your results too much. If this happens, use only those limiters that are necessary.
Try searching in a database that specializes in a certain subject. If you need a subject-specific database, try the Subject Guides or Course Guides created by Northwestern's subject librarians. Be flexible and be prepared to try several different databases.
Think more broadly about your topic. For example, if you're researching the impact of Basque terrorism on a specific town in Spain, you might broaden your search to look at Basque terrorism more generally. Or you might do separate searches for different aspects of your topic.