Re-using text from one's own previously published papers: an exploratory study of potential self-plagiarism

A preliminary, two-part study explored the extent to which authors reuse portions of their own text from previously published papers. All 9 articles from a recent issue of a psychology journal were selected as target papers. Up to 3 of the most recent references cited in each of the target articles and written by the same authors were also obtained. All target articles and their corresponding references were stored digitally. Then, using specialized software, each reference was compared to its target article to assess the number of strings of text identical to both papers. Only one of the nine target articles reused significant amounts of text from one of its references. To explore further the possibility of additional text reuse, the references in each of the 9 sets of papers were compared against each other. The new comparison identified 5 pairs of papers with a substantial number of identical strings of text of 6 consecutive words in length or longer, but most of the reused text was confined to the Method section. The results suggest that some of these authors reuse their own text with some frequency, but this was largely confined to complex methodological descriptions of a research design and procedure.