Plagiarism is the act of presenting the words, ideas, or images of another as your own; it denies authors or creators of content the credit they are due. Whether deliberate or unintentional, plagiarism violates ethical standards in scholarship (see APA Ethics Code Standard 8.11, Plagiarism).
Writers who plagiarize disrespect the efforts of original authors by failing to acknowledge their contributions, stifle further research by preventing readers from tracing ideas back to their original sources, and unfairly disregard those who exerted the effort to complete their own work.
To avoid plagiarism, provide appropriate credit to your sources by adding author–date in-text citations for direct quotations and ideas (e.g., credit the originators of theories). If you model a study after one conducted by someone else, give credit to the author of the original study.
If you wish to reprint or adapt tables, figures, and images or to reprint long quotations or commercially copyrighted test items, you must provide more comprehensive credit in the form of a copyright attribution and may need permission from the copyright holder to use the materials. Even images from the internet that are free or licensed in the Creative Commons need a copyright attribution if you are reproducing them in your paper. For more information about copyright and permissions, see Sections 12.14–12.18 of the Publication Manual (7th ed.).
What specifically “counts” as plagiarism?
Although many cases of plagiarism are straightforward (e.g., passages of text copied from another source without attribution), other cases are more challenging to evaluate. Usually, using incorrect citations (e.g., misspelling an author’s name, forgetting or mistyping an element in a reference list entry, or citing a source in the text that does not have a corresponding reference list entry) is not considered plagiarism if the error is minor and attributable to an editorial oversight rather than an intentional attempt to steal someone’s ideas. However, such errors may still result in deductions on an academic assignment or a request for revision of a manuscript submitted for publication.
Publishers and educators may use plagiarism-checking software (e.g., iThenticate, Turnitin) to identify cases in which entire papers have been copied, passages of specified lengths match, or a few words have been changed but content is largely the same (the latter is known as patchwriting).
Self-plagiarism is the presentation of your own previously published work as original; like plagiarism, self-plagiarism is unethical. Self-plagiarism deceives readers by making it appear that more information is available on a topic than really exists. It gives the impression that findings are more replicable than is the case or that particular conclusions are more strongly supported than is warranted by the evidence. It may lead to copyright violations if you publish the same work with multiple publishers (sometimes called duplicate publication).
What specifically “counts” as self-plagiarism?
Some institutions may consider it self-plagiarism if a student submits a paper written for one class to complete an assignment for another class without permission from the current instructor. Using the same paper in multiple classes may violate the academic integrity policy, honor code, or ethics code of the university.
However, incorporating previous classwork into one’s thesis or dissertation and building on one’s own existing writing may be permissible; students who wish to do this should discuss their ideas with their instructor or advisor and follow their university’s honor code, ethics code, or academic policies when reusing their previous work.
In specific circumstances, authors may wish to duplicate their previously used words without quotation marks or citation (e.g., in describing the details of an instrument or an analytic approach), feeling that extensive self-referencing is undesirable or awkward and that rewording may lead to inaccuracies. When the duplicated material is limited in scope, this approach is permissible.
General guidelines for using an acceptable amount of duplicated material are in the Publication Manual in Sections 1.16 and 8.3.
An exception to the prohibition against self-plagiarism is publishing a work of limited circulation in a venue of wider circulation. For example, authors may publish their doctoral dissertation or master’s thesis in whole or in part in one or more journal articles. In such cases, authors would not cite their dissertation or thesis in the article text but rather acknowledge in the author note that the work was based on their dissertation or thesis.
Similarly, an article based on research the authors described in an abstract published in a conference program or proceeding does not usually constitute duplicate publication. The author should acknowledge previous presentation of the research in the article’s author note.
Seek clarification from your journal editor or course instructor if you are concerned about duplicate publication or self-plagiarism.