American Psychological Association (APA) style
is a widely accepted style of documentation, particularly in the social sciences
. APA style specifies the names and order of headings, formatting, and organization of citations
, and the arrangement of tables
, and appendices
, as well as other manuscript and documentation features. APA style
uses Harvard referencing
, also known as the author-date system of citations and parenthetical referencing, keyed to a subsequent list of "References." The APA Publication Manual
provides basic guidelines for documenting both print and electronic resources.
Sections and subsections
An APA style paper typically has the following sections, each of which starts on a new page.
- Title Page
- Author Note
- Tables (new page for each table)
- Figure captions
- Figures (new page for each figure)
- Level 5: CENTERED UPPERCASE HEADING
- Level 1: Centered Uppercase and Lowercase Heading
- Level 2: Centered, Italicized, Uppercase and Lowercase Heading
- Level 3: Flush Left, Italicized, Uppercase and Lowercase Side Heading
- Level 4: Indented, italicized, lowercase paragraph heading ending with a period.
in text are done using Harvard 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 parenthesis. 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 (no initials) 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.
" However, 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 authors or more
The correct format is (First Author et al., Year). In the reference section, all six authors' names should be included.
- Pauling et al. (2005) discovered a possible genetic cause of alcoholism.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 alcoholismMultiple 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).
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." (The preference for Arabic names now is to hyphenate the prefix so that it remains with the surname.)
Book by one author
- Sheril, R. D. (1956). The terrifying future: Contemplating color television. San Diego: Halstead.Book by two authors or more
- Smith, J., & Peter, Q. (1992). Hairball: An intensive peek behind the surface of an enigma. Hamilton, ON: McMaster University Press.Article 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: OtherWorld Books.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 journal with 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.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 newspaper
- Wrong, M. (2005, August 17). "Never Gonna Give You Up" says Mayor. Toronto Sol, p. 4.Government document
- Revenue Canada. (2001). Advanced gouging: Manual for employees (MP 65–347/1124). Ottawa: Minister of Immigration and Revenue.
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 the access date
- include all other relevant APA style details for the sourceInternet article based on a print source (With exact formatting of original)
- Marlowe, P., Spade, S., & Chan, C. (2001). Detective work and the benefits of colour versus black and white [Electronic version]. Journal of Pointless Research, 11, 123–124.Internet article based on a print source (Formatting differs from original)
- Marlowe, P., Spade, S., & Chan, C. (2001). Detective work and the benefits of colour versus black and white. Journal of Pointless Research, 11, 123–124. Retrieved October 25, 2007, from http://www.pointlessjournal.com/colour_vs_black_and_white.htmlArticle in an Internet-only journal
- Blofeld, E. S. (1994, March 1). Expressing oneself through Persian cats and modern architecture. Felines & Felons, 4, Article 0046g. Retrieved October 3, 1999, from http://journals.f+f.org/spectre/vblofeld-0046g.htmlArticle in an Internet-only newsletter
- Paradise, S., Moriarty, D., Marx, C., Lee, O. B., Hassel, E., et al. (1957, July). Portrayals of fictional characters in reality-based popular writing: Project update. Off the Beaten Path, 7 (3). Retrieved October 3, 1999, from http://www.newsletter.offthebeatenpath.news/otr/complaints.htmlStand-alone Internet document, no author identified, no date
- What I did today. (n.d.). Retrieved August 21, 2002, from http://www.cc.mystory.life/blog/didtoday.html [Fictional entry.]Document available on university program or department website (note that APA spells website Web site)
- Rogers, B. (2078). Faster-than-light travel: What we've learned in the first twenty years. Retrieved August 24, 2079, from Mars University, Institute for Martian Studies Web site, http://www.eg.spacecentraltoday.mars/university/dept.html [Fictional entry.]Electronic copy of a journal article, three to five authors, retrieved from database
- Costanza, G., Seinfeld, J., Benes, E., Kramer, C., & Peterman, J. (1993). Minutiæ and insignificant observations from the nineteen-nineties. Journal about Nothing, 52, 475–649. Retrieved October 31, 1999, from NoTHINGJournals database. [Fictional entry.]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: Random House/Listening Library. Book on tape
- Nix, G. (2002). Lirael, Daughter of the Clayr [Cassette Recording No. 1999-1999-1999]. New York: Random House/Listening Library.Movie
- Gilby, A. (Producer), & Schlesinger, J. (Director). (1995). Cold comfort farm [Motion picture]. Universal City, CA: MCA Universal Home Video.
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 X2 tests: General format: Χ2([df error], N = [total sample size]) = [Chi-squared obtained], p = [p-value].
- *Example: X2(4, N = 24) = 12.4, p = .015.
Graph and table layout
- 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.
- 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 styles (personal communication, November 3, 2002).
- CitePrecise - FREE Comprehensive APA Reference Examples
- APA Books: APA Style – List of APA style-related books published by the American Psychological Association.
- High Quality APA Style and Format Guide
- 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.
- "Citation Machine" – Citation style generator (APA, MLA, Chicago, Turabian).
- Introduction to APA Style - Hypertextual electronic workshop hosted by the Online Writing Lab (OWL), Department of English, Purdue University.
- "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.