American Psychological Association (APA) style mandates a consistent appearance and structure of research papers, and a uniform way of crediting sources. This page provides a quick guide to the most salient features of APA style. See also this page and this page for more information and advice on APA style. Other useful sources of information are the Purdue OWL website and the APA Style Blog.

There are a few rules to keep in mind. The paper should be in 12-point, Times New Roman font, double-spaced, with 1-inch margins. Even references and block quotes should be double-spaced.
    Page 1 of the paper is the title page. Page 2 is the abstract. The final page or pages are for references. The references should begin on their own page
    If you include headings and subheadings in your paper, there is a hierarchy of APA headings to follow. Briefly: Major headings, often reserved for “Method,” “Results,” “Discussion,” etc., should be centered, boldfaced, and written with the mix of capital and lowercase letters typical of book titles. Secondary headings should be the same as primary headings, except flush left. Tertiary headings should be flush left but indented, only the first letter of the heading should be capitalized, and the heading should end with a period. Please see pages 62-63 of the APA Publication Manual (6th edition) for direction on creating appropriate headings.
    At the top of every page of an APA paper should be a running head, consisting of the title of the paper at the left (in ALL CAPS) and the page number at the right. A briefer version of the title may be used. On only the first page should the title be preceded by “Running head:”

The reference list goes at the end of the paper. Footnotes in APA style are reserved for ancillary information, clarifications, musings, and other extraneous stuff—not for references. APA style also does not have traditional endnotes. Instead, the references are listed alphabetically, by the last name of the first author of the source, at the end of the paper. Every source in your reference list should be cited somewhere in your paper (and vice versa).
    The basic format for a reference to a journal article is as follows (most sample references are imaginary):

Smith, J. C., Jones, R., & Lee, B. K. (2011). Multistable perception and the frontoparietal cortex: New research on a vexing  problem. Journal of Attention and Neuroscience, 41(3), 231-259. doi:10.1236/btlmp.20.1.11

For a book it would be as follows:

Kramer, D. & Lewis, R. L. (2018). The psychology of everyday life. Harrisburg, PA: Phillips House Press.

The reference for a chapter in a book would look like this:

Brown, L. (1998). Semantic maps. In F. Richter & G. M. Sanderson (Eds.), Logic, language, and psychology: New perspectives. Tampa, FL: Southeastern Press.

   Websites are trickier. The general rule is to look, as hard as you possibly can look, for an author for the site, whether that is a person or a corporate author. For example, if the site is an informational page from the Arizona Department of Public Health, and no person is named as author, consider that entity the page’s author. If no personal or corporate author is to be found, then the title is moved to first position in the reference, followed by the date. Here are three website examples, the first with a personal author, the second with a corporate author, the third with no named author:

Coren, S. (2017, November 30). Do dogs respond more accurately to words or gestures? Psychology Today. Retrieved from https://www.psychologytoday.com/blog/canine-corner/201711/do-dogs-respond-more-accurately-words-or-gestures

American Psychological Association. (n.d.). Understanding the Ritalin debate. Retrieved from http://www.apa.org/topics/adhd/ritalin-debate.aspx

Avatar therapy may ease symptoms of depression. (2018, March 18). Retrieved from http://www.psychnews.com/avatar-therapy/

For the second reference above, note that, because there was no date on the website, “n.d.”—i.e., “no date”—is put inside the parentheses. For the third reference above, the proper in-text citation would be (“Avatar Therapy,” 2018).

Every time you take a fact, interpretation, opinion, or quote from a source, you must cite the source in text. These citations are called, reasonably, in-text citations. In contrast to many other citation styles, APA style requires author(s) and date to be listed in the in-text citation.
    Let’s say you took a fact from an article by Smith, Jones, and Lee. You can cite it in text this way:

Very few studies have considered the neuroscience of multistable perception in children (Smith, Jones, & Lee, 2011).

Or like this:

Smith, Jones, and Lee (2011) report that few studies have considered the neuroscience of multistable perception in children.

Note that in subsequent references this study will be Smith et al. (2011). You would be wise to bookmark page 177 of your APA Publication Manual. There you will find this and other rules for in-text citations. They can be summarized as follows:

• For citations to sources with one or two authors, list all the authors all the time.
• For citations to sources with three to five authors, list all authors the first time, then only the first author, plus “et al.”, for subsequent references.
• For citations to sources with six or more authors, list only the first author, plus “et al.”, every time.

When two sources are cited in the same in-text citation, they are arranged alphabetically and separated by a semicolon.
   A final rule: When two articles by the same author(s) are published in the same year, distinguish them by placing an “a” or “b” (and so on) after the year in the reference and the in-text citation. So: Chen (2016a). See chapter 6 of the APA Publication Manual (6th ed.) for more direction on unusual cases such as this.

Q: What are those letters and numbers that come at the end of an article reference?

A: That is the Digital Object Identifier (DOI), a unique identifier assigned to journal articles. The DOI, without a period following it, should be given in a reference where it exists. If a DOI for an article is tough to find, you can use an article title to search for a DOI here. If you read an article in print, it may (if it is a recent publication) have a DOI—in which case, include it. If a DOI is not listed on printed article, you don’t need to include it.

Q: In a reference, do I need to give the website for an article I find on Vanderbilt’s databases?

A: No. You do not need to give the web address unless you took the article from the open web (i.e., not from databases you have access to only through Vanderbilt). The purpose of a reference is to direct readers back to the original source. Not all potential readers have access to proprietary databases. So for an article found on ERIC or PsycINFO, give the article information as usual, plus the DOI.

Q: Do I need to give the date I retrieved an article from the Internet?

A: Generally no. APA says that dates should be provided only when a page—such as a Wiki—is likely to change.