APA style

American Psychological Association (APA) Style is a set of rules developed to assist reading comprehension in the social and behavioral sciences. Designed to ensure clarity of communication, the rules are designed to "move the idea forward with a minimum of distraction and a maximum of precision." The Publication Manual of the American Psychological Association contains the rules for every aspect of writing, especially in the social sciences from determining authorship to constructing a table to avoiding plagiarism and constructing accurate reference citations.

Early editions

The Publication Manual was establshed in 1929 as a seven-page document with a set of procedures to increase the ease of reading comprehension (APA, 2009a, p. xiii). Created under the sponsorship of the United States National Research Council, its originators included psychologists, anthropologists, and publishing professionals.

In 1952, the booklet was expanded and published as a 55-page supplement in Psychological Bulletin with revisions made in 1957 and 1967 (APA, 1952, 1957, 1967). The first edition covered word choice, grammar, punctuation, formatting, journal publication policies, and "wrapping and shipping" (APA, Council of Editors, 1952, p. 442).

In response to the growing complexities of scientific reporting, subsequent editions were released in 1974, 1983, 1994, and 2001. Primarily known for the simplicity of its reference citation style, the Publication Manual also established standards for language use that had far-reaching effects. Particularly influential were the "Guidelines for Nonsexist Language in APA Journals," first published as a modification to the 1974 edition, which provided practical alternatives to sexist language then in common usage. The guidelines for reducing bias in language have been updated over the years and presently provide practical guidance for writing about race, ethnicity, age, gender, sexual orientation, and disability status (APA, 2009, pp. 70–77; see also APA, 2009b).

Sixth Edition of the Publication Manual

The sixth edition of the Publication Manual of the American Psychological Association was released in July 2009 after 4 years of development. The Publication Manual Revision Task Force of the American Psychological Association established parameters for the revision based on published criticism, user comments, commissioned reviews, and input from psychologists, nurses, librarians, business leaders, publishing professionals, and APA governance groups (APA, 2007a, 2007b). To accomplish these revisions, the Task Force appointed working groups of four to nine members in seven areas: Bias-Free Language, Ethics, Graphics, Journal Article Reporting Standards, References, Statistics, and Writing Style (APA, 2009, pp. xvii-xviii).

Thoroughly reorganized and updated, the sixth edition was significantly revised to incorporate the technological advances that had affected virtually all areas of scientific communication since the previous edition was published (APA, 2001). Specific revisions in the sixth edition include

• expanded ethics guidance on determining authorship, sharing data, plagiarism, and self-plagiarism;
• a new section on Journal Article Reporting Standards (JARS), stressing the need for precision and consistency in reporting methodology and providing practical guidelines for achieving this consistency;
• new, simplified heading style for easier comprehension of online articles;
• expanded guidelines on reducing bias in language, including a new section on presenting historical language that is inappropriate by present standards;
• new guidelines for reporting inferential statistics as well as thoroughly revised and expanded tables of statistical abbreviations and measures;
• new procedures and examples for the electronic presentation of data;
• new formats for electronic references, with a focus on the digital object identifier, or DOI, as the most reliable way to locate online information;
• expanded information about the publishing process, including a new discussion of the peer review process;
• all new examples and illustrative material to demonstrate revised standards of style.

APA Style online

With the release of the sixth edition of the Publication Manual, there are multiple places where you can learn about APA Style online. Among them are the following:

Resources on apastyle.org.

• Main apastyle.org page
• Learning resources page, including links to free tutorials, an online course, and other content arranged by subject
• Free tutorials:
  • The Basics of APA Style
  • What's New in the Sixth Edition
• FAQs about APA Style
• Online course:
  • Mastering the Sixth Edition

Resources on the APA Style Blog

The APA Style Blog is a repository for current information about APA Style. It addresses commonly asked questions from readers as well as areas the manual may not address, such as

• how to cite social media, like
  • Twitter,
  • Facebook,
  • Kindles (or other e-book readers), and
  • Wikipedia articles.

It also answers questions about how to cite regular references as well as electronic references.

Other topic areas include

• databases
• how to use DOIs or digital object identifiers
• grammar and usage questions
• Lists, including how to use
  • lettered lists,
  • numbered lists,
  • bulleted lists, and
  • how to choose what type of list you need.

The "categories" on the right-hand side of the blog show the different areas that have been explored, and users can also search the site using a Google search box to find answers to their questions.

Follow the APA Style Team on Twitter

You can follow the APA Style Team on Twitter to get updates on all things related to APA Style, including announcements about new blog posts, tips and tricks on writing and style, new features on apastyle.org, and more. The Twitter username is @APA_Style.

Errors in the First Printing of the Sixth Edition

Despite multiple reviews of the manuscript at the copyediting and proofreading stages by senior editors, staff realized shortly after the manual had gone to press that the sample papers contained errors. They took prompt action to correct the errors and to post the fully corrected papers on the APA Style website where they were made available for viewing and downloading. Staff concurrently examined the rest of the manuscript and found the following additional errors:

• In 188 style guidelines, two errors were made, and one of these was a punctuation error.
• In almost 1,000 examples provided to illustrate those rules, 36 errors were made (roughly half of these occurred in the sample papers, which were subsequently corrected and posted online). Another 10 occurred in the 374 examples that were provided in the reference chapter.
• Five clarifications to text were made. These were not errors but rather clarified and expanded text, for example, adding a second example for both a blog post and a blog comment.
• Three pages of nonsignificant typographical errors were corrected. These included such things as changing an em dash to an en dash, changing a minus sign to a hyphen, and correcting for added space that was automatically added when a sample form was reproduced.

In the interest of transparency (and following the same procedure that was followed for the fifth edition), staff posted all of the corrections online in a single document on October 1, 2009, and shortly thereafter alerted users to the existence of the corrections in a blog entry. On the same day the corrections were posted, an individual posting to the Educational and Behavioral Sciences Section listserv (EBBSS-L) of the American Library Association alerted readers to what she described as the "many" errors in the first printing and speculated that "some but not all" would be corrected in a second printing. On October 5, 2009, APA staff responded to the note clarifying that errors were found in the sample papers, that the papers had been corrected and posted online, that the substantive guidance in the manual was correct and accurate as printed, and that a full list of corrections could be found at the APA Style website.

On October 13, 2009, the article "Correcting a Style Guide" was published in the online newspaper Inside Higher Education that included interviews with several individuals who defined the errors as "egregious" (Epstein, 2009)]. The article, along with rumors spread on various listervs, resulted in exaggerated accounts of both the magnitude and the extent of the errors, with some reports on Amazon.com claiming more than 80 pages of errors had occurred.

APA responded to the increasing confusion by issuing an apology and implementing a return/replacement program for purchasers who wished to exchange their first printing copies for second printing copies of the Publication Manual. The first edition copies returned to APA were destroyed. The second and all subsequent printings of the Publication Manual have been fully corrected.

Sections and subsections of papers using sixth edition

Because of changes in some areas from the fifth edition, such as References, the information listed below should be used with caution as it does not reflect the sixth and most recent edition of the Publication Manual or its corrected second printing.

Papers or articles following the 6th edition of The Publication Manual of the American Psychological Association (APA Style) will typically include the following sections, each of which starts on a new page:

1. Title Page
2. Abstract
3. Text (body of paper)
4. References
5. Footnotes
6. Tables (new page for each table)
7. Figures (new page for each figure, include figure caption below the figure on the same page---this is a change from the 5th ed.)
8. Appendices (optional---may not be present for all papers)

The guidelines for manuscript preparation can be found in Chapter 8 of the 6th edition of the Publication Manual on p. 228. It covers margins, typeface, line spacing, and other matters.

Note that these guidelines are intended specifically for submitting to APA Journals. Many universities have other requirements that add to or supersede the requirements in the APA Style manual.

Headings

The use of headings aids in establishing the hierarchy of the sections of a paper to help orient the reader. Topics within a paper that have equal importance will have the same level of headings throughout the paper. For example, in a paper with multiple experiments, the heading for the Method section for Experiment 1 should be at the same level as the heading for the Method section for Experiment 2.

Headings can also function as an outline to reveal the paper's organization. This is particularly true when the paper is submitted to APA journals. Also, avoid having one sub-section heading in a paper. Use at least two subsections with any given section or none at all.

APA’s heading style consists of five possible levels of subordination. Level 1 is the highest level and Level 5 is the lowest level. Most papers will use two or three levels. Levels are always used consecutively, beginning with Level 1.

1. Level 1: Centered, Boldface, Uppercase and Lowercase Headings
2. Level 2: Left-aligned, Boldface, Uppercase and Lowercase Heading
3. Level 3: Indented, boldface, lowercase heading with period.
4. Level 4: Indented, boldface, italicized, lowercase heading with period.
5. Level 5: Indented, italicized, lowercase heading with period.

You can read more about them and see examples in the APA Style Blog category for headings.

Citation

Reference citations in text are done using parenthetical referencing. Most usually, this involves enclosing the author's surname and the date of publication within parentheses, separated by a comma, generally placed immediately after the reference or at the end of the sentence in which the reference is made. However, it is also common for the authors to be the subject or object of a sentence. In such a case only the year is in parentheses. In all cases of citation, author name(s) are always followed immediately by a year, and years are never presented without author name(s) immediately preceding it. In the case of a quotation, the page number is also included in the citation.

Full bibliographic information is then provided in a Reference section at the end of the article. APA style defines that the reference section may only include articles that are cited within the body of an article. This is the distinction between a document having a Reference section and a bibliography, which may incorporate sources which may have been read by the authors as background but not referred to or included in the body of a document.

Single author

Format should be Author's last name followed directly by a comma, then the year of publication. When one makes the reference to the author(s) directly as a part of the narrative, then only the year (and page number if needed) would remain enclosed within parentheses. The same holds for multiple authors.

A recent study found a possible genetic cause of alcoholism (Pauling, 2005).

Pauling (2005) discovered a possible genetic cause of alcoholism.

Two authors

Authors should be presented in order that they appear in the published article. If they are cited within closed parentheses, use the ampersand (&) between them. If not enclosed in parentheses then use expanded "and".

A recent study found a possible genetic cause of alcoholism (Pauling & Liu, 2005).

Pauling and Liu (2005) discovered a possible genetic cause of alcoholism.

Three to five authors

With three to five authors, the first reference to an article includes all authors. Subsequent citations in the same document may refer to the article by the principal author only plus "et al." All authors must be present in the references section.

A recent study found a possible genetic cause of alcoholism (Pauling, Liu, & Guo, 2005).

Pauling, Liu, and Guo (2005) conducted a study that discovered a possible genetic cause of alcoholism.

Pauling et al. (2005) discovered a possible genetic cause of alcoholism.

A recent study found a possible genetic cause of alcoholism (Pauling et al., 2005).

Six or seven authors

The correct format in the text is (First Author et al., Year) or First Author et al. (Year).

Brown et al. (2005) discovered a possible genetic cause of alcoholism.

In the reference section, all authors' names should be included if there are six or seven authors.

Eight or more authors

In the text, the first and all subsequent references should be to First Author et al. (Year) or (First Author et al., Year).

In the reference list, list the first six authors, and then put an ellipsis (three periods), and then list the last author.

Brown, A.B., Johnson, C., Laird, K., Howard, O. P., Evans, S., . . . Pritchard, J. (2004). ..... (study has eight or more authors)

Multiple publications, same author

If an author has multiple publications that you wish to cite, you use a comma to separate the years of publication in chronological order (oldest to most recent). If the publications occur in the same year, the Publication Manual recommends using suffixes a, b, c, etc. (note that corresponding letters should be used in the reference list, and these references should be ordered alphabetically by title).

Recent studies have found a possible genetic cause of alcoholism (Pauling, 2004, 2005a, 2005b).

Pauling (2004, 2005a, 2005b) has conducted studies that have discovered a possible genetic cause of alcoholism

Multiple publications, different authors

Follow the rules for one author above, and use a semicolon to separate articles. Citation should first be in alphabetical order of the author, then chronological.

Recent studies found a possible genetic cause of alcoholism (Alford, 1995; Pauling, 2004, 2005; Sirkis, 2003)

Direct quotes

The same rules as above apply here, the format being (Author, Year, Page Number).

When asked why his behavior had changed so dramatically, Max simply said, "I think it's the reinforcement" (Pauling, 2004, p. 69).

Reference list

The APA style guide prescribes that the Reference section, bibliographies and other lists of names should be accumulated by surname first, and mandates inclusion of surname prefixes. For example, "Martin de Rijke" should be sorted as "de Rijke, M." and "Saif Al-Falasi" should be sorted as "Al-Falasi, S." For names in non-English languages, follow the capitalization standards of that language. For each of the source types below a hanging indent should be used where the first line is flush to the left margin and all other lines are indented.

Print sources

Book by one author

• Sheril, R. D. (1956). The terrifying future: Contemplating color television. San Diego, CA: Halstead.

Book by two authors

• Kurosawa, J., & Armistead, Q. (1972). Hairball: An intensive peek behind the surface of an enigma. Hamilton, Ontario, Canada: McMaster University Press.

Chapter in an edited book

• Mcdonalds, A. (1993). Practical methods for the apprehension and sustained containment of supernatural entities. In G. L. Yeager (Ed.), Paranormal and occult studies: Case studies in application (pp. 42–64). London, England: OtherWorld Books.

Dissertation (PhD or masters)

• Mcdonalds, A. (1991). Practical dissertation title (Unpublished doctoral dissertation). University of Florida, Gainesville, FL.

Article in a journal with continuous pagination (nearly all journals use continuous pagination)

• Rottweiler, F. T., & Beauchemin, J. L. (1987). Detroit and Narnia: Two foes on the brink of destruction. Canadian/American Studies Journal, 54, 66–146.

• Kling, K. C., Hyde, J. S., Showers, C. J., & Buswell, B. N. (1999). Gender differences in self-esteem: A meta-analysis. Psychological Bulletin, 125, 470–500.

Article in a journal paginated separately

• Crackton, P. (1987). The Loonie: God's long-awaited gift to colourful pocket change? Canadian Change, 64(7), 34–37.

Article in a weekly magazine

• Henry, W. A., III. (1990, April 9). Making the grade in today's schools. Time, 135, 28–31.

Article in a weekly magazine with DOI

• Hoff, K. (2010, March 19). Fairness in modern society. Science, 327, 1467-1468. doi:10.1126/science.1188537

Article in a print newspaper

• Wrong, M. (2005, August 17). "Never Gonna Give You Up" says Mayor. Toronto Sol, p. 4.

Electronic sources

For electronic references, websites, and online articles, APA Style asserts some basic rules, including to

• direct readers specifically to the source material using URLs which work
• include retrieval date ONLY when content is likely to change (e.g., wikis)
• include all other relevant APA Style details for the source

Online article based on a print source, with DOI (e.g., a PDF of a print source from a database)

• Krueger, R. F., Markon, K. E., Patrick, C. J., & Iacono, W. G. (2005). Externalizing psychopathology in adulthood: a dimensional-spectrum conceptualization and its implications for DSM-V. Journal of Abnormal Psychology, 114, 537-550. doi:10.1037/0021-843X.114.4.537

Online article based on a print source, without DOI (e.g., a PDF of a print source from a database)

• Marlowe, P., Spade, S., & Chan, C. (2001). Detective work and the benefits of colour versus black and white. Journal of Pointless Research, 11, 123–127.

Online article from a database, no DOI, available ONLY in that database (proprietary content--not things like Ovid, EBSCO, and PsycINFO)

• Liquor advertising on TV. (2002, January 18). Retrieved from http://factsonfile.infobasepublishing.com/

OR

• Liquor advertising on TV. (2002, January 18). Retrieved from Issues and Controversies database.

Article in an Internet-only journal

• McDonald, C., & Chenoweth, L. (2009). Leadership: A crucial ingredient in unstable times. Social Work & Society, 7. Retrieved from http://www.socwork.net/2009/1/articles/mcdonaldchenoweth

Article in an Internet-only newsletter (eight or more authors)

• Paradise, S., Moriarty, D., Marx, C., Lee, O. B., Hassel, E., . . . Bradford, J. (1957, July). Portrayals of fictional characters in reality-based popular writing: Project update. Off the Beaten Path, 7. Retrieved from http://www.newsletter.offthebeatenpath.news/otr/complaints.html

Article with no author identified

• Britain launches new space agency. (2010, March 24). Retrieved from http://news.ninemsn.com.au/technology/1031221/britain-launches-new-space-agency

Article with no author and no date identified (e.g., wiki article)

• Harry Potter. (n.d.). In Wikipedia. Retrieved March 12, 2010, from http://en.wikipedia.org/wiki/Harry_Potter

Entry in an online dictionary or reference work, no date and no author identified

• Verisimilitude. (n.d.). In Merriam-Webster's online dictionary (11th ed.). Retrieved from http://www.merriam-webster.com/dictionary/verisimilitude

E-mail or other personal communication (cite in text only)

• (A. Monterey, personal communication, September 28, 2001)

Book on CD

• Nix, G. (2002). Lirael, Daughter of the Clayr [CD]. New York, NY: Random House/Listening Library.

Book on tape

• Nix, G. (2002). Lirael, Daughter of the Clayr [Cassette Recording No. 1999-1999-1999]. New York, NY: Random House/Listening Library.

Movie

• Gilby, A. (Producer), & Schlesinger, J. (Director). (1995). Cold comfort farm [Motion picture]. Universal City, CA: MCA Universal.

Statistical expressions in APA

Some of the more common examples are given below. Italics and spaces need to be carefully noted.

Note on Probabilities

There are two ways to report statistical probability: pre-specified probability given as a range below the chosen alpha level and exact probability given as a calculated p-value. Since most statistical packages calculate an exact value for p, the Publication Manual recommends that exact p-values should be reported.

• Example: p < .05
• Example: p = .031 (preferred)

Exceptions, where a pre-specified probability range may be preferred, include large or complex tables of correlations or when the p-value is particularly small (e.g., p < .001).

Reporting F-tests

General format: F([df-between], [df-within]) = [F-obtained], p = [p-value], [eta-squared obtained] = [value].

• Example: F(2, 50) = 9.35, p < .001, η² = .03.

If a p-value is not significant, then the letters ns are substituted, or the precise p-value is substituted prefaced by an equals sign.

• Example: F(2, 50) = 1.35, ns.
• Example: F(2, 50) = 1.35, p = .18. (preferred)

If an F-value is less than 1, thereby implying that it can never be statistically significant, then neither the F-value itself, nor the associated p-value, is reported.

• Example: F(2, 50) < 1.
• Example: F < 1.

Reporting t-tests

General format: t([df error])= [t-obtained], p = [p-value], [Cohen's d obtained] = [value].

• Example: t(9) = 2.35, p = .043, d = .70.

Reporting $\chi ^{2}$ tests

General format: $\chi ^{2}$([df error], N = [total sample size]) = [Chi-squared obtained], p = [p-value].

• Example: $\chi ^{2}$(4, N = 24) = 12.4, p = .015.

Graph and table layout

• Graphs
  • should not have tick marks for the measures
  • should have titles for the x and y axis
  • should not have outline around the graph
  • should not have minor lines on the chart
  • The legend should either not exist if the graph is simple or should be inside the chart
  • need to be on a figure captions page, with an explanation of the data represented
  • do not have page numbers, and should have penciled in, on the back the top and the figure caption that corresponds to it.
• Tables
  • do have page numbers
  • do not have vertical lines

Other non-print sources

No personal communication is included in the reference list; instead, parenthetically cite the communicators name, the fact that it was personal communication, and the date of the communication in your main text only.

(E. Robbins, personal communication, January 4, 2001).

A. P. Smith also claimed that many of her students had difficulties with citation style (personal communication, November 3, 2002).

See also

• Citation
• MLA style
• Comparison of reference management software

References

• American Psychological Association). (2010). The Publication Manual of the American Psychological Association (6th ed.). Washington, DC: Author. ISBN 9781433805622
• American Psychological Association). (2001). The Publication Manual of the American Psychological Association (5th ed.). Washington, DC: Author. ISBN 9781557987914

External links

• Introduction to APA Style - Hypertextual electronic workshop hosted by the Online Writing Lab (OWL), Department of English, Purdue University.
• APA Style—Reference List/In-Text (pdf)
• Create References APA - Free Generator APA references
• APA Referencing from Laerd.com - Free Comprehensive APA Reference Examples
• APA "Citation Styles" Online Guide - Resource hosted by the Department of English, University of Illinois at Urbana-Champaign.
• Apacite – "A BibTeX style which closely follows American Psychological Association style citations, providing a very good match."
• APA.cls – Resource compiled by Athanassios Protopapas, Institute for Language and Speech Processing (ILSP), Athens, Greece.
• APA Guide Basics Summary (pdf) - Webpage summary of APA Rules.
• APA Style - APA Style Online home page.
• CiteFast - Free Citation Generator
• "Citation Machine" – Citation style generator (APA, MLA, Chicago, Turabian).
• Amacite – Automatic citation style generator and library for books powered by Amazon.com (APA, MLA).
• "KnightCite: A Project of Hekman Library – APA, MLA, and Chicago Style citation generator hosted by Calvin College.
• "NoodleBib Express" – Style advice, citation creator (APA, MLA, Chicago, Turabian).
• Psychology with Style: A Hypertext Writing Guide (for the 5th edition of the APA Manual) (February 1, 2007 - Version 5.014). - Teacher's Guide compiled by Mark Plonsky, Ph.D., Professor of Psychology, University of Wisconsin–Stevens Point.