Is there such a thing as self-plagiarism?  

The Oxford English Dictionary defines the word ‘plagiarize’ as “take the work or idea of someone else and pass it off as one's own”. Taken in this sense, the term ‘self-plagiarism’ is an oxymoron. Nevertheless, the term is widely used and is defined in the Mirriam Webster dictionary as “The re-use of one’s own words, ideas or artistic expressions from preexisting material, especially without acknowledgement of their earlier use”. We prefer the use of the ethically neutral term ‘text recycling’ to cover most situations where authors use previously published text in a new paper.

Text recycling can occur in many different contexts. Editors of research journals need to exercise good judgement in deciding when it is permissible and when it is not. It is not meaningful to merely consider similarity percentages generated by plagiarism detecting software and set cut off levels. In evaluating text recycling, the JNSF considers intent to be of paramount importance. Is there an attempt to mislead by not providing references to previously published work? Related to intent is the issue of novelty. Does the paper contain sufficient new material worth disseminating to the scientific community? The answers to these two questions generally provide a reasonable basis to form a judgement on permissible and non-permissible text recycling.

One situation in which text recycling is permissible is in the description of experimental methods which have been published before, but need to be restated in the context of a new paper using the same method but with different substances and different values for parameters such as mass, volume, temperature and time. In such a situation, the attempt to reduce the similarity percentage of the paper by modifying the sentences and phrases used can result in an awkward text lacking the clarity and focus of the original. Ironically, it can even be conceived as an attempt to mislead!