The American Psychological Association (APA) citation format is a widely used format for essays, research papers and theses especially relating to social sciences. The APA citation format was originally introduced as a seven page guideline and appeared in the Psychological Bulletin in 1929.

Writing an essay in the APA style helps both the writer and the reader. It helps the writer to better organize the essay. And should the writer wish to publish it in a psychological journal the citation format must be in APA. It helps the reader to review the essay better, locate references easily and do further research if required. However some writers consider this format as not the easiest one.

An essay or research paper under the APA referencing has the following components. There is a title page. Then there is an abstract. This is optional and left to the discretion of the tutor. Next is the body of your paper, and finally the reference list.

The abstract (if asked for by the tutor) is a gist of the whole paper. It gives the reader an idea of what the complete essay contains. Based on this abstract a reader normally decides whether or not to read the whole essay. The abstract immediately follows the title page and normally does not exceed 120 words.

APA paper may have an introduction. The purpose of the introduction is to familiarize the reader with what the essay will be dealing with in detail. It is written on the premise that the reader is new to the subject. The title page of an essay under the APA format must meet the following requirements.

The paper's title, the name of the author and the institute of affiliation should appear centered on the upper half of the page. The other elements of the title page are the header and a running head. The header is an abbreviation of the title and is no longer that one or two words. The running head should be within 50 characters.

In addition to the above there are a few requirements that are basic. It is required that an essay is typed on paper that is 8.5 inches by 11 inches. It also requires that the all-around margin be 1 inch. The line spacing should be double. Every page of the essay should have a header and a page number and the two should appear in the right hand corner. This should appear on the title page also.

There is also the parenthetical documentation method for in-text citation when using the language or idea of someone else. The way in-text citation is done differs a little if the work cited is by one or more authors or from a secondary source or is a direct quote. In APA the parenthetical documentation should include the last name of the author and the year of publication. If the name of the author forms a part of the essay text the year of publication is alone mentioned in parenthesis.

As per the APA citation format the reference page should be a separate page with the works cited arranged in alphabetical order. The references should be double spaced with no spaces between references. If a reference runs to more than one line, all subsequent lines should be indented.