Your topic must be manageable and fit the scope, audience, length and time limits of your assignments. Sometimes this means that you will need to narrow your original idea. Consider:
What are your personal connections to the topic?
Why does the topic interest you?
What are the more controversial or intriguing aspects?
Do you want to focus on a certain time period or geograhical area?
Generate a series of questions about your topic and see which one interests you most.
Example (from St. Martin's handbook):
Emily, a student writer is interested in the effect of advertising on American identity. This topic is too broad for her assigment. So she posted on facebook, asking her friends to post their most "American" products. She chose from among their ideas (Coke and Pepsi). So she narrowed her focus to the effect of Coke and Pepsi ads on American identity.
Broaden your topic
You might find that your topic is so narrow that there is not a lot published about it. In this case you need to broaden.
There are several ways to do this:
Choose less specific terms for your search. For example flowers instead of zinnias.
Try your search in GOOGLE Scholar. Sometimes you will get more results. Also, try clicking the "related article" link at the bottom of a citation.
Rememer some of those limits you added to narrow your search? Remove them.
If you were focusing on a particular time period or geographic area, broaden or remove this limit
If you were focusing on a single perspective, like sociological or psychological, try removing it and see what you get.
For example, alcohol use by students at UGA in 1999 might be too narrow. Try expanding it to alcohol use by students at UGA, or even college students and alcohol use.