I'm writing a research paper on romance novels and who reads them but I'm having trouble writing my statement of purpose.
Since you've put this in Social Sciences and tagged it with "methods of social research" I assume you are writing some sort of social sciences paper on this topic. However, it would be helpful to tell us more about what you are trying to accomplish with this paper. Without that, we can only guess at what your purpose is.
If I were trying to write a social sciences paper about this topic, my most likely question would be about the demographic characteristics of people who read romance novels. I would want to know about their sex, age, marital status, job status, and income. I'd like to know about their happiness levels too, but I doubt that would be available in the statistics. My statement of purpose (I am assuming that this is a very short statement) would be something like:
"Romance novels are stereotypically seen as the entertainment form of bored housewives, usually from the lower reaches of the middle class. In this paper, I will atttempt to determine who really reads these books. I will investigate the demographic characteristics, such as sex, age, marital status, job status, and income to determine if there are characteristics common to most readers of this genre."