The American Psychological Association (APA) format provides a set of rules and guidelines for the structure of research papers. Widely used in the social and behavioral sciences, APA style is best known for its rules on citing sources in your work. Writers must document sources in-text as they are used, followed by corresponding full-length citations in a reference list. In most cases, you will follow the APA's author-date system for citing sources in your text.
Cite your source in the text of your APA style document in one of two ways. You can include the author's last name and date in parentheses at the end of the sentence containing the information you borrowed. Alternatively, APA style allows you to include the author's name as part of your narrative while enclosing just the date of the work in parentheses.
Follow these examples, as adapted from Purdue University's Online Writing Lab (OWL):
According to Morris (2000), APA style is widely used in architecture schools.
Eighty percent of the schools surveyed report using APA style (Morris, 2000).
Cite works with two authors as follows:
Jones and McKinney (1999) report that one in five students passed the test.
Of those who passed, one-third scored in the 90th percentile (Jones & McKinney, 1999).
Document works with three to five authors like this:
(Barry, Berry, Burry, & Barley, 2007)
For subsequent citations, use (Barry et al., 2007). In cases with six or more authors, use "et al." in the first and all subsequent citations.
Use an organization's name in lieu of a person's last name when an organization serves as the author for one of your sources. For example:
According to the American Citation Association (1999), APA style is popular among graduate students.
If the organization uses a recognized acronym, you may use it in every in-text citation after the first. For example:
Forty-five percent of study participants reported no side effects (American Medical Association [AMA], 2010).
In fact, most thought the sports drink tasted good (AMA, 2010).
Include the appropriate page number in addition to the author's last name and date when using a direct quote from a source. Purdue's OWL notes that while it's not mandatory, the APA urges you to include a page number as well when paraphrasing or summarizing a quote from a source. For example:
He claimed that "the technicians had every right to follow up" on the case (Jones, 2008, p. 212).
He noted that he was unsure why the media stirred up such controversy (Jones, 2008, p. 213).