It is critical that the focus of your paper topic is suitably narrow. "Suitably" is the key here. Your professor is always looking for detail and depth, but a 20-page essay will be able to provide detail and depth on a broader topic, while an 8-page essay will require a narrower topical focus to get the same detail and depth. Consider these two questions:
- Is the topic that you have chosen so huge that summary of existing research and the sources you've found will barely fit in the limit imposed by the instructor? The topic is likely too broad.
- Is the topic that you have chosen so narrow that you can summarize the sources you've found, analyze them, and describe existing research in half the length of the requested page limit? The topic is likely too narrow.