Narrow down the subject (topic) to a central theme that includes researchable terms.
The first step in a research project is to distinguish between a subject and a central theme.
A subject is the discipline or academic subject and it is too broad to research.
By focusing on a central theme within the subject, you are narrowing your research to make it more manageable.
For example, biology would be a subject that is too broad to research.
You could narrow down to the subject of health but that is still too broad.
If you focus on anxiety as a health issue, you have narrowed even more.
An example of a central theme for the subject of anxiety might be how testing anxiety affects the physical health of high school students.