Sometimes your selected topic will be so narrow you won't be able to find enough sources when you research it. If that's the case, you can broaden your topic using the same 5 W questions listed above.
Really narrow topic: causes and treatment of anorexia in African American teenage males in St. Louis in the 1980s
To narrow a topic that is too broad for a particular assignment, ask yourself the following 5 W questions.
Broad topic: eating disorders
Once you've answered these questions, combine different combinations of the areas you're interested in to create an interesting, manageable research topic.