The Fine Line Between Plagiarism and Necessary Repetition

My senior thesis student this year came to my office today to ask a question as he’s starting to work on writing his thesis. I’ve given him copies of the theses of the last couple of students to work in my lab, and asked him to start on a draft of the background sections. He was worried that he wouldn’t be able to make the background sections sufficiently distinct from the corresponding sections in the earlier theses.

This is a sort of tricky point when it comes to issues of academic honesty in science. Scientific questions always have definite right and wrong answers, and that limits the range of possible responses. It can be difficult to catch cheaters in science classes, because the right answers will necessarily look pretty much the same. The only unambiguous way to catch people copying off one another is to spot two papers making the same improbable mistakes. (Which happens fairly often, actually. I don’t have a problem with students working together on homework– in fact, I encourage it– but I do ask that they report who they worked with. Inevitably, though, at least one group won’t, and they’re always surprised when I write “You worked with X, Y, and Z on this. In the future, please state that clearly on the paper.)

The same problem happens, to a lesser degree, in scientific writing. Two papers, or two theses, written on work from the same lab will often have opening sections that are more or less identical. Not word-for-word identical, mind, but the same ideas, in the same order, in very similar notation. There are only so many ways to report the exact same facts, and all of the papers from a given lab will tend to require the same set of background information.

The key, of course, is to avoid word-for-word copying. This can occasionally be a problem, particularly if some previous student has come up with a particularly elegant way of describing some situation, but in most cases, it’s not that hard to avoid. You just start with a blank page, and fill it up in your own words, and you’ll end up with something that’s different enough to pass muster.

But it is something to guard against, and I’m not surprised that my student was worried about it.