The inevitable student question: How long does this paper have to be? The inevitable professor answer: As long as it needs to be to get the job done. Perhaps a more helpful answer is this: If you choose a topic which is carefully scoped so that it is not too big or too small, then a background section of a research paper might be roughly eight pages long in APA format, which is double-spaced. Add a title page, abstract page, and reference page(s) to the paper per APA guidelines. All together, that sounds like about 11 or 12 pages in APA format.