APA Style focuses on making your paper clear. Including all information necessary to understand your syntheses of other papers and allowing others to comprehend your empirical studies.
In the 1920's, psychologists worried about the enormous overload of information, just as we do today. They had no idea what would be coming, but they designed styles that would allow readers to find the important information quickly.
APA Style includes guidance on several aspects of the writing up research.
This guide will point you to APA's website for Style and Grammar Guidelines, showing you where to find the information you need.