Here’s Why a Plagiarism Checker Won’t Save You From Plagiarism

Maybe I’m dating myself when I say this, but: I really hate “plagiarism-checking” software.

I taught college English briefly in the mid-2010s. Every class had at least one student obsessed with the idea of software like Turnitin: “Do you use Turnitin to check for plagiarism?” “Are you going to be putting our papers through a plagiarism checker?” “If Turnitin says my paper is 12 percent plagiarized, will I fail?” “What if the software says I plagiarized, will I get kicked out of school?”

My answers to these questions (no, no, maybe, and maybe) only seemed to confuse them more. I found myself having to devote an entire class period not only to what plagiarism is, but why plagiarism-checking software won’t save you from it.

The reason lies in how the software works.

Plagiarism checkers see words, not meaning.

Plagiarism is the act of passing off someone else’s intellectual work as your own. There are several different ways to pass off someone else’s intellectual work as your own, but plagiarism-checking software can only catch one of these: The use of someone else’s specific words to describe the same idea.

That’s because plagiarism checkers aren’t actually reading your paper. Rather, the software scans for groups of letters and spaces in your paper that also appear in other papers, articles, blog posts, etc. available online. If it finds similar groupings, the software will flag them as “plagiarism.”

“I copied and pasted from my sources” is the only form of plagiarism a plagiarism checker can see. But it isn’t the only form of plagiarism. It’s just the most blatant.

Plagiarism checkers may see “plagiarism” where there is none.

Because plagiarism checkers are scanning for identical or similar letter clumps, they’re vulnerable to identifying “plagiarism” where there is none.

A plagiarism checker will flag a long quote as plagiarism, even though it is not plagiarized as long as the quote is properly cited.

The use of citations as a saving throw was one of the things my plag-checker-happy students struggled with the most. “How can I ever quote anything if the computer tells me it’s plagiarism?” The idea that it’s not plagiarism if you tell me who said it and where could not, for some reason, compete with their fear of the software.

Plagiarism checkers will also flag some terms of art as plagiarism, even though they are specific terms that can’t be swapped out with synonyms.

For example: In law, the term “motion in limine” is a term of art. A motion in limine is a specific type of legal motion – one for which there isn’t really an alternate descriptor.

If I write a paper on “The Best Ways to Deal With a Motion in Limine,” and I use phrases like “motion in limine,” “pre-trial conference,” and “evidentiary standard” (all of which are related terms of art) over and over, there’s a good chance a plagiarism checker will flag this as plagiarism. It’s not. It’s the use of specific terms with specific meanings – substitutions will not do.

Realizing this, some purveyors of plagiarism checkers set thresholds for their matches. For instance, a paper whose plagiarism percentage is below 10 percent may not get flagged as “plagiarism” by the system.

While this may help deal with terms of art, however, threshold percentages still aren’t enough to ensure that plagiarism checkers always catch plagiarism.

Plagiarism checkers may not see “plagiarism” where it does exist.

As I mentioned above, word-matching is only one form of plagiarism – the most obvious form. But plagiarism includes any attempts to pass off someone else’s intellectual work as your own.

Plagiarism checkers are notoriously bad at catching unattributed summary and paraphrase, or the practice of stating someone else’s information in your own words without mentioning that you learned that information from someone else. Because the letter-clumps don’t match, the software doesn’t see unattributed summaries or paraphrase as plagiarism.

But it is. The operative element here is not “did I copy word for word?” It’s “did I tell the reader where this information came from, if it came from a source outside my own brain?”

Plagiarism checking software’s inability to catch summary and paraphrase, except in the most obvious cases of article-spinning (and even then, not always), is the number-one reason I hate plagiarism checkers. Students learn that the problem is copying word for word, and so they don’t prioritize proper citations – the thing that will actually protect them from any claims of plagiarism.

It always interested me to see how my students reacted to the news that I don’t use plagiarism-checking software. Most of them seemed relieved, as if they’d learned the panopticon was down for maintenance. A few seemed to think they’d get away with copying and pasting as a result. (The latter were always nastily surprised.)

The truth is, most student plagiarism is visible from space, especially for a teacher who has been reading what they write from the very first day of class. I notice when an 18 year old from the inner city suddenly starts to sound like a middle-school teacher from rural Oklahoma, for instance. And, contrary to the beliefs of some of my students, I don’t prize that middle-school teacher’s voice over the student’s. On the contrary: I’m disappointed that I don’t get to hear from the student – especially when the reason I write, and the reason I teach, is that I firmly believe in the power of writing to free us to be exactly who we are.

Plagiarism checking software limits that freedom without benefiting my students or my teaching. So no. I don’t use it. And I don’t recommend anyone else does, either.

What’s your take on plagiarism checkers? Comment and let me know!