The American Psychological Association format is an academic style of writing that is used extensively in behavioral and social sciences as well as many other disciplines. Most times, APA style does not recommend the use of footnotes or endnotes. However, sometimes it is appropriate to use them when you need to provide supplementary content or the status of copyright permissions.
Footnote Versus Endnote
The terms "footnote" and "endnote" refer to additional information provided for the reader through the use of superscript numbers and explanatory text. A footnote appears at the bottom of the page on which it was inserted. Endnotes, however, are listed together on a separate page at the end of the document. As the writer, you should choose the most appropriate layout for your paper. If you choose to keep the notes together and place them at the end of the paper, this page should be titled with a level-one heading of "Footnotes" (without quotes). Indent five spaces from the left margin and insert the footnote text, including the superscript number.
Because content footnotes provide additional information to the reader -- such as clarification or explanation -- you don't need to follow any specific format. However, you must ensure that footnotes do not distract the reader from the main text by including irrelevant or confusing information. It is also important to focus on one singular idea in a footnote rather than multiple lengthy elaborations. If you feel a lengthy elaboration is warranted, this information is better placed within the text of your writing or as an appendix than as a footnote.
Copyright footnotes attribute the source of reprinted or adapted figures and tables, long quotes, and scale and test items. Use a numbered footnote only to supply the source of long quotes. For tables, use a table note; for figures, credit the source at the end of the figure's caption. For copyright permission footnotes, follow this formatting.
Journal From [or The data in column 2 are from] "Title of Article," by A. B. Author and C. D. Author, year, Title of Journal (italicized), Volume (italicized), p. #. Copyright [year] by the Name of Copyright Holder. Reprinted [or adapted] with permission.
Example: From "How the iPad Changed my Life," by R. J. Taylor and M. A. Schimmel, 2012, Educational Technology (italicized), 5 (italicized), p. 24. Copyright 2012 by R. J. Taylor and M. A. Schimmel. Reprinted with permission.
Book From [or The data in column 2 are from] Title of Book (italicized) (p. xxx), by A. B. Author and C. D. Author, year, Place of Publication: Publisher. Copyright [year] by the Name of Copyright Holder. Reprinted [or adapted] with permission.
Example: The data in column 1 are from Intercultural Competence in Practice (italicized) (p. 125), by B. Snyder and L. A. Crown, 2013, Thousand Oaks, CA: Sage Publications. Copyright 2013 by Sage Publications. Adapted with permission.
General Footnote and Endnote Considerations
Footnotes or endnotes should be numbered consecutively with superscript numbers. They always come after any punctuation mark except a dash, which the superscript number precedes. If you use a footnote within parentheses, the footnote comes inside the closing parenthesis. When referring to a previous footnote in your writing, treat it as an in-text citation rather than rewriting the footnote. For example: A sleep study of similarly aged females yielded comparable results (see Footnote 4).