The 20^th-century playwright Wilson Mizner is credited with having said “When you steal from one author, it’s plagiarism; if you steal from many, it’s research!” (Ironically, this quote is often misattributed to Steven Wright, one of my favorite comedians.) Last month I wrote about using material that had been copyrighted or trademarked. This month, I would like to discuss plagiarism and the ethics of copying others’ (and even your own) previous work. There are two cases that I typically see as an editor involving plagiarism: one is extremely serious and one is becoming more serious.

The first, extremely serious, type of plagiarism is when an author copies material from someone else and does not properly reference the source. Frequently, the material is verbatim text, figures, or equations from some other published or unpublished paper, but the source paper is not cited, attribution is not given to the author(s) of the previous paper, and sometimes the information is misrepresented as new, original, and significant. The submitting author hopes that OSA does not catch this plagiarism.

My belief is that most authors know this activity is unethical; nevertheless, it is motivated by an intense desire to publish papers in reputable journals in order to enhance one’s career. Some countries have such an emphasis on quantity and quality of publications as criteria to obtain jobs and secure promotions that plagiarism behavior has become more common over the past 10 years. Fortunately, journals are more capable of detecting copied material in submissions using Crosscheck by iThenticate and other tools, and they are putting more effort into educating authors about ethical standards. See OSA’s Guidelines for Ethical Practices in Publication (https://www.osapublishing.org/submit/review/ethics.cfm) and the special editorial on plagiarism (https://www.osapublishing.org/submit/review/plagiarism_2013.pdf) for more information.

When one of these cases arises, I work closely with OSA’s Editorial Ethics Review Panel, and I push for the most severe penalty available. There is no excuse for copying others’ work and claiming that it is new, original, and significant. This is blatant plagiarism. If you mention someone else’s work in your paper to explain or provide context for your research, you must provide a full citation, including the title, authors, and publication name of the original work. If you use verbatim material, this should be indicated by the use of quotation marks.

The second type of plagiarism, which for many years I admit I did not consider to be serious, is self-plagiarism. We receive submissions where half of the article is verbatim or significantly similar to a previously published paper by the same author. I don’t have any problems with an Applied Optics submission being based largely on a conference paper. In fact, OSA policy specifically allows it, as long as certain guidelines are followed, such as meeting standard journal criteria for originality, novelty, and quality (https://www.osapublishing.org/submit/review/general_policies.cfm#). Many of us are guilty of using verbatim material from a previous journal paper. In most cases, it can be considered background material and it does not mean that you are not presenting new and interesting material in the new paper. What is an acceptable amount of previous work that you can use? Is it 10%, 20%, or 50%? At OSA, there have been a number of discussions on this topic. I don’t have an answer to this. I agree with many of my colleagues that 50% republished material is too much. However, if I get a complaint that 10% of a new submission is self-plagiarized, then I don’t take any action. This is an issue that I expect to become more serious in the future, and there definitely will be more discussions among the journals’ Editors-in-Chief. I will say that if you do include any previous material, then you need to properly cite the work, even if (and especially if) the new work is based on a conference paper. Also, you should be sure to disclose this when submitting the paper to Applied Optics.

I hope this discussion is helpful to some of you. When even the editors get confused, it is sometimes worthwhile to talk through these policies. OSA’s resources on ethics, plagiarism, and conference papers mentioned above should help to guide you.

Mark Twain (another of my favorites) said “How lucky Adam was. He knew when he said a good thing, nobody had said it before.”