When writing research papers, most researchers would have come across the term “et al.” This is the abbreviation for a Latin phrase—written variously as et alii (masculine), et aliae (feminine), and et alia (neuter)—which means “and others.” The term “et al.” is mainly used for in-text citations of research papers having multiple authors, although some style guidelines also advocate the use of “et al.” in the reference list.
Ethical publication emphasizes that authors should provide an inclusive list of their sources in their manuscripts. This is because citations give credibility to a research work and help avoid plagiarism by crediting the original research work on which the present work is based. However, different journals and organizations follow different reference citation styles, which make it difficult to generalize the use of “et al.” when citing references.
Given below are a few citation style guidelines that outline the use of “et al.”
American Psychological Association (APA) Style Guide (6th edition): For references having three to five authors, APA states that all the author surnames (last names) should be cited at the first instance, and citations thereafter should include the first author’s surname followed by “et al.” But for research papers with six or more authors, the surname of the first author is always cited followed by “et al.” Note that “et al.” should not be in italics, and “al” should be followed by a period.
Example: Three to five authors, (Kernis, Cornell, Sun, Berry, & Hallow, 1993) or Kernis, Cornell, Sun, Berry, & Hallow (1993) will be used as the first citation, and (Kernis et al., 1993) or Kernis et al., (1993) should be used in subsequent citations.
Six or more authors: (Harris et al., 2001) or Harris et al. (2001)
Modern Language Association (MLA) Style Manual: For research papers having three or more authors, MLA states that, for the reference list, the first author’s surname should be cited, followed by a comma, then the rest of the name, followed by “et al.” For in-text citations, the first author’s surname is followed by “et al.”
Example: Russell, Tony, et al. (2016) for reference list; Russell et al. (2016) for in-text citation.
Chicago Manual of Style (CMS): For four to ten authors, write out all names in the bibliography but only the first author’s name followed by “et al.” in in-text citations. For more than ten authors, only the first seven are listed in the bibliography, but the first author’s name followed by “et al.” is used in in-text citations. Note that “et al.” is not italicized.
Example: Acoose et al. (2008) or (Acoose et al., 2008) for in-text citation.
As previously mentioned, different style guidelines have adopted different rules for using “et al.” So, the best way to use “et al.” is to check the guidelines of your target journal or organization and follow the style accordingly.