Generally, the APA or the American Psychological Association, as how wikiHow would want to define it as, is one of the most commonly used styles for writing research and scientific papers, usually leaning to the areas of business, mathematics, psychology, sociology, economics, criminal justice as well as nursing. Writing Resources - How to Write an APA Research Paper ... An APA-style paper includes the following sections: title page, abstract, introduction, method, results, discussion, and references. Your paper may also include one or more tables and/or figures. Different types of information about your study are addressed in each of the sections, as described below.