Taking a paragraph, or for that matter, even a unique sentence from another source, and using it in our own writing without enclosing the material in quotations constitutes plagiarism. Similarly, inappropriate paraphrasing may also be classified as plagiarism.

The available evidence indicates that one of the reasons writers misappropriate text is because they may be unfamiliar with the concepts and/or language with which s/he is working. The ability to properly paraphrase technical text depends in large part on an author’s conceptual understanding of the material and his/her mastery and command of the language and of her knowledge of, and ability, to convey discipline-specific expressions typically used to describe relevant phenomena, laboratory processes and procedures, etc. Accordingly, it is relatively easy to thoroughly paraphrase others’ work when we have a full grasp of the issues and of the language involved. For example, studies show that when asked to paraphrase a short paragraph, students (Roig, 1999; Walker, 2008) as well as university professors (Roig 2001) are more likely to appropriate and, therefore, plagiarize text when the original material to be paraphrased is made up of technical language likely to be unfamiliar to them, than when the topic is a familiar one and the original is written in plain language.

Obviously, inexperienced writers (e.g., students) have the greatest difficulty paraphrasing the advanced technical text often found in the primary scientific literature. In an effort to introduce them to primary sources of information in a given discipline, college students are often required to write a research paper from articles published in professional journals. For those students who must complete this type of assignment for the first time, and, in particular for foreign students whose primary language is not English, writing a research paper can be a daunting task. This is because scholarly prose: 1) can be very intricate, 2) adheres to unique stylistic conventions (e.g., use of the passive voice in the biomedical sciences), and 3) relies heavily on jargon and unusual expressions that novice writers have yet to master. Consequently, students need to create an acceptable academic product that is not only grammatically correct, but also demonstrates knowledge of the concepts discussed. These circumstances force many such students to rely on close paraphrases of the original text. Unfortunately, such writing can result in a charge of plagiarism.

An analogous situation can occur at the professional level when authors see the need to paraphrase a complex process or methodology. As indicated earlier, traditional scholarly conventions provide us with the option to re-use any material by enclosing it in quotation marks or by block-quoting it (i.e., indenting the material within both margins) with some type of indication (e.g., a footnote) as to its origin. Therefore, if the text is so technical that it would be very difficult or nearly impossible to modify substantially without altering its meaning, then perhaps it would be best to leave it in the original author’s wording, enclose it in quotation marks (or block-quote it), and include a citation. However, unlike literature or philosophy, quoting in certain disciplines (e.g., biomedical sciences) is not encouraged (see Pechnick, 2001). One would be hard pressed to find an entire sentence quoted, let alone a short paragraph, in the pages of prestigious biomedical journals (e.g., Nature, Science, New England Journal of Medicine).

In sum, the reality is that in many instances, scientific prose and diction can be very difficult to paraphrase. To illustrate the difficulties inherent in paraphrasing highly technical language, let’s consider the following paragraph from a report recently published in Science (Lunyak, et al., 2002).

Mammalian histone lysine methyltransferase, suppressor of variegation 39H1 (SUV39H1), initiates silencing with selective methylation on Lys⁹ of histone H3, thus creating a high-affinity binding site for HP1. When an antibody to endogenous SUV39H1 was used for immunoprecipitation, MeCP2 was effectively coimmunoprecipitated; conversely, αHA antibodies to HA-tagged MeCP2 could immunoprecipitate SUV39H1 (Fig. 2G).²

Here is an attempt at paraphrasing the above material:

The H3 methyltransferase SUV39H1 mediates gene silencing of neuronal genes in Rat-1 fibroblasts by methylating lysine 9 of histone H3, thus creating a binding site for the heterochromatin protein HP1 and subsequent formation of a chromatin complex involving multiple silencing factors including the methyl-CpG- binding protein MeCP2 and SUV39H1 itself (Lunyak, et al., 2002).¹

Unlike the previous examples of appropriate paraphrasing, the above example does not embody as many textual modifications. In order for the exact meaning of the original Science paragraph to be preserved in the present case, many of the same terms must be left intact in the paraphrased version. Although synonyms for some of the words may be available, their use in the specific context of the original paragraph is simply not appropriate. For example, take the word affinity, which is defined as “that force by which a substance chooses or elects to unite with one substance rather than with another” (Dorland, 2000) or, in its more recent edition, “a special attraction for a specific element, organ or structure” (Dorland, 2011). Roget’s Thesaurus (Moorhead, 2002) lists the following synonyms for affinity: liking, attraction, relations, similarity. Although it might be possible to rewrite the first sentence using the synonym “attraction,” this alternative fails to capture the precise meaning conveyed by the original sentence, given how the term is used in this area of biomedical research. The word affinity has a very specific denotation in the context in which is being used in the Science paragraph and it is the only practical and meaningful alternative available. The same can be said for other words that might have synonyms (e.g., binding, silencing, site). Other terms, such as methylation and antibodies are unique and do not have synonyms. In sum, most of the rest of the technical terms (e.g., immunoprecipitation, endogenous, coimmunoprecipitated) and expressions (e.g., HA-tagged, high-affinity, mammalian histone lysing methyltransferase) in the above paragraph are extremely difficult, if not impossible, to substitute without altering the intended meaning of the paragraph. As a result, a properly paraphrased version such as the one offered above will share many common elements with the original and thus, applying the strict definitions of paraphrasing provided by some writing guides might render the above paraphrase as a borderline, or an outright, case of plagiarism.

It may be worth noting that the ”correct paraphrase” version of the Lunyak, et al (2002) paragraph that had been included in the previous version of this guide and which is reproduced immediately below had been written by a nonspecialist in that field and contained a subtle misinterpretation of the processes described in the original material paragraph:

A high affinity binding site for HP1 can be produced by silencing Lys⁹ of histone H3 by methylation with mammalian histone lysine methyltransferase, a suppressor of variegation 39H1 (SUV39H1). MeCP2 can be immunoprecipitated with antibodies prepared against endogenous SUV39H1; on the other hand, immunoprecipitation of SUB39H1 resulted from aHA antibodies to HA-tagged MeCP2.²

Such subtle misrepresentations illustrates the fact that highly technical descriptions of a methodology, phenomena, etc., can be extremely difficult to properly paraphrase and, to do so, a writer mush have a thorough conceptual understanding of the concepts and processes being described. It is perhaps for this reason that ORI’s definition of plagiarism (Office of Research Integrity, 1994) provides the following caveat:

ORI generally does not pursue the limited use of identical or nearly- identical phrases which describe a commonly-used methodology or previous research because ORI does not consider such use as substantially misleading to the reader or of great significance.

All of the above considerations serve to illustrate the reason why an operational definition of proper paraphrasing/plagiarism (i.e., how many consecutive words taken from the original constitutes plagiarism) is impractical, not to mention the fact that there are certain stock phrases, perhaps even entire sentences that occur with some frequency in unrelated journal articles (e.g., “the results obtained do not support the hypothesis”). Nevertheless, and in spite of the above clarification provided by ORI, a responsible writer has an ethical responsibility to readers and to the author/s from whom s/he is borrowing, to always respect and acknowledge their intellectual content.