Introduction to the APA style guide

APA style is the most common guide for academic writing in the social and behavioral sciences disciplines. In addition, many academic journals require APA style for submissions.

The manual is published by the American Psychological Association. The official name of the style guide is Publication Manual of the American Psychology Association, but it is commonly known as the APA style manual, or just “APA.” The manual was updated in 2020 to the 7th edition.

Writing. The APA style manual offers specific guidance on almost any topic writers encounter, including the basics of how to punctuate and capitalize, when to italicize, when to abbreviate, and how to use commas, colons, and brackets. Writers will also find examples of properly formatted tables, figures, and captions. The 2020 edition includes new guidance specifically for authors of theses and dissertations.

Format. APA guidelines include recommendations for font style and size (any legible, widely available font is acceptable), line spacing (double-space everything with the exception of content in tables and figures, footnotes, and equations), paragraph indentation (first line, one-half inch), and pagination (sequentially, placed in the upper-right corner with or without a running head, depending on your institution’s requirements).

Citations and references. APA uses a parenthetical author-date format to cite sources in the text and a corresponding list of references placed at the end of the body of the paper. The APA manual offers clear examples of how to cite virtually any source, from journal articles and books to legal references and online videos. The 2020 edition now allows works with three or more authors to be written with et al. in every citation.

The APA style manual is available from most bookstores and can be ordered online from multiple vendors. At this time, there is no Web version of the manual, although APA maintains a searchable blog written by APA experts who answer questions posed by scholars, students, and other writers.

APA resources

Publication Manual of the American Psychology Association, 7th ed. (2020). ISBN: 9781433832161 (paperback).
APA blog: http://blog.apastyle.org/
APA website: https://www.apa.org/

Differences between popular style guides

Style guides differ in their handling of many aspects of writing and formatting, including spelling and punctuation. The main concerns for scholarly writers involve citation and reference list formats.

Spelling. The style guides have a few differences in terms of spelling, particularly with regard to numbers. APA style requires writers to spell out numbers in letters if they are below 10 or if they begin a sentence. Numbers 10 and above are written numerically. For example, “The researchers tested a sample of 22 children using two versions of the test instrument.” CMS and Turabian, on the other hand, require that most numbers be written out rather than presented numerically (e.g., one, ten, twelve, twenty, one hundred sixty-two, two thousand, 2,341, 199,452).

Punctuation. Most academic style guides and publishers use the Oxford (serial) comma (e.g., “The researchers offered the children red, blue, and green pencils.” In contrast, journalistic style guides do not use the Oxford comma (e.g., “The researchers offered the children red, blue and green pencils”). Placement of commas and periods in relation to quotation marks (inside or outside) depends on geographical location (American English or United Kingdom English), rather than on style guidelines.

Number of spaces between sentences. A big change starting with the 7th edition is that APA prefers one space after terminal punctuation. Many institutions and departments, however, still prefer writers use two spaces. Always confirm with your institution on its preference. In some cases, the writer can choose in which case it is important to be consistent in your use of punctuation and spacing throughout your document.

Citation format. An important area where style guides differ is in the treatment of citations. Some style guides use footnotes or end notes, for example, Chicago/Turabian and Bluebook styles, rather than in-text citations (sometimes called the author-date referencing style, typical in APA, MLA, and Harvard style). Table 1 below shows examples of subtle differences between citation formats in APA, CMS/Turabian (author-date format), MLA, Harvard, and Bluebook styles.

Keep in mind that the purpose of a citation is to give your reader the means to locate the sources providing the support for the thoughts, claims, quotes, images, or models that you use in your paper. It’s important to format your citations correctly; however, it is more important that you cite your sources, no matter what format you use. Failing to cite your sources places you at risk of plagiarism, which can have serious consequences.

Reference list format. Style guides also differ somewhat in the content and format of the list of references. Apart from the name of the list itself (APA: “References”; MLA: “Works Cited”; CMS/Turabian: “Bibliography” or “References,” depending on the CMS citation style chosen), lists are formatted differently. Some are listed in alphabetical order; others are numbered and appear in the order in which the sources are cited in the paper. Many sources will include a URL.

Remember, the purpose of the list of references is to provide enough information so your reader can look up the source to find out more about it. Before you submit your paper, make sure all your URLs are accurate, current, and reasonably accessible to a scholarly audience.

The format of a typical entry for a source from a book is shown in Table 2 for APA, CMS/Turabian (both author-date and footnote/endnote formats), MLA, Harvard, and Bluebook styles. APA’s preferred format for DOIs and URLs has been updated for the 7th edition in 2020.

Heading levels and formats. APA 7th edition in 2020 has been updated with revisions to the five possible heading levels used in APA-style documents.