Plagiarism is committed when one author uses another work ( typically the work of another author) without permission, credit, or acknowledgment. Plagiarism take different forms, from literal copying to paraphrasing the work of another.
Literal copying is reproducing a work word for word, in whole or in part, without permission and acknowledgment of the original source. Literal copying is obvious plagiarism and is easy to detect by comparing the papers in question.
Substantial copying is reproducing a substantial part of a work, without permission and acknowledgment of the original source. In determining what is "substantial", both the quantity and the quality of the copied content are relevant. Quality refers to the relative value of the copied text in proportion to the work as a whole. Where the essence of a work has been reproduced, even if only a small part of the original work, plagiarism may have occured. For example, relatively short extract from a piece of music may be instantly recognizable and may constitute a substantial part.
In addition to judging the quantity and quality of the copied content, you should consider the following question: Has the author benefited from the skill and judgment of the original author? The degree to which the answer to this question is "yes" will indicate whether substantial copying has taken place
Copying may take place without reproducing the exact words used in the original work, i.e. without literal or substantial copying. This type of copying is known as paraphrasing, and it can be the most difficult type of plagiarism to detect.
To determine whether unacceptable paraphrasing has occurred, you should apply a test similar to that for substantial copying: Look at the quantity and quality of what has been taken and also at whether the second author has benefited from the skill and judgment of the first author. If it seems clear, on a balance of probabilities, that the second author has taken without permission or acknowledgment all or a substantial part of the original work and used it to create a second work, albeit expressed in different words, then such use amount to plagiarism.
The complainant must be made aware that the matter cannot be investigated unless at some point the journal editor informs the corresponding (or complained-about) author (due process) and likely the other journal.
The first stage must be first simple comparison of the relevant (two) texts. This can be simple side-by-side comparison by the editor for the simpler forms of plagiarism or a more thoughtful analysis by the editor if paraphrasing or types of 'self-plagiarism' are alleged.
Frequently asked questions
Then the editor should correspond with the corresponding (or complained-about) author. In some cases for confidentiality purposes it may be best for the editor to summarize (rather than simply forward) the complaint. It may be useful for the editor to involve other peer reviewers, editorial board members, or experts in the relevant field (anonymously as to the complainant and if possible as to the identity of the complained-about authors), using standard peer review procedures, to review the texts (especially if the allegation is a more complex form of plagiarism). Legal review may be appropriate if the complainant or their publisher is alleging copyright infringement (the Elsevier legal team will provide this).
In the communication to the corresponding/complained-about author (see Form letter A1), the editor should indicate that it is possible that the matter may be referred to the institution or company where the research took place or any other relevant institution or agency (for example a funding agency) unless the author provides a reasonable explanation (accepted as reasonable by the editor). Note that the editor may believe that referral to the institution or agency is not necessary (unlike with respect to claims about authorship or fraud, where the institution has responsibility for the conduct at their institution and an obligation to investigate, plagiarism may simply be a mistake - perhaps a type of unattributed copying - or may be considered to be the personal responsibility of the author rather than an institutional responsibility).
Then a corrigendum or retraction would be the normal remedy. Note that there may still be disagreement concerning the appropriate description.
It is normally sufficient to simply indicate that the complained-about work included substantial parts copied without attribution from a prior work.
Although the complainant may feel a stronger statement would be more appropriate - and if in fact the wrong-doer simply "passed off" someone else’s paper as their own, a stronger statement would most likely be appropriate, but with legal review for defamation.
Ultimately the editor may need to make a judgment as to the appropriate language for the statement, if there is no consensus, and should do so in consultation with Elsevier staff.
Then the editor will have to consider whether the author's explanation is reasonable. Normally the editor would also inform the complainant of the author's explanation and seek comment (see Form letter B).
Then it would be fair for the editor to draw an inference that there is some substance to the complaint.
Then the editor must inform the corresponding (or complained-about-) author and complainant that the journal will seriously consider the decision of the institutional review. Note, however. that the editor may still determine that the result of the institutional review is insufficient or inaccurate.
Then this should be reviewed with the complainant (perhaps the complainant is better placed to make the complaint directly with the institution).
Then the editor will be expected to make a determination, in the reasonable judgment of the editor, as to the underlying facts, and to make a recommendation to Elsevier (and possibly the society for a society journal), which Elsevier staff will implement normally through a corrigendum or the retraction process.
These are available for a second opinion (*). This is often the time for the editor to discuss the case with his/her publishing contact within Elsevier and agree what action, if any, needs to be taken.