Whitson, Chapter 4 offers other ways to think about your topic. She describes concept mapping and mindmapping. There is also a very good tutorial from the UCLA College library that will help you understand how to narrow or broaden your topic. Use what works best for you in order to understand how to develop points from broader to narrower ideas. Here is another example.
Many topics are interdisciplinary.
Availability of research materials will be important, especially if you are dependent on electronic sources or those of your local library. No library can have everything and the collection ususally reflects the academic institution's curricula and areas of research. Top Selecting a Topic Asking questions Identifying concepts Finding words and synonyms When you have narrowed your topic, state precisely what you'd like to find out about it. If it helps, state your topic as though you were talking to a librarian describing to her or him what your information need is. The more specific you can be, the more focused your research will be.