The APA format refers to the style rules and guidelines set forth in a reference book called "The Publication Manual of the American Psychological Association." APA style is an editorial style adopted by most social and behavioral sciences as the preferred format for presentation of written material. The purpose of following the APA format is consistent use of punctuation, abbreviations, headings, reference citations and other elements.
A paper written in APA format typically contains four main sections: the title page, the abstract, the main body and a references list. The document should be typed in 12-point font, double-spaced and with a one-inch margin on all sides. A page header must be on the top left of each page, and the page number must appear on the top right. References to other research and resources require both in-text citations and inclusion in a references list.
The APA format was developed to improve clarity of communication and to minimize the bias in language by providing guidance on word choice. The manuscript structure is designed to provide minimal distractions from the content while reading.
Journals of the American Psychological Association, various other scientific journals, textbooks, most academic research in psychology and much of the publications in education and the social sciences follow the APA style of writing.
Several social scientists developed the APA format in 1929.