Plagiarism: how to spot it and what to do about it

Whether it’s done accidentally, unthinkingly or with malice aforethought, plagiarism is something all editors should be primed to spot. This article considers five potential signs of plagiarism and explores how to discuss it tactfully with publishers and authors.

As a giant recycling machine, generative AI has added a whole new dimension to the concept of plagiarism (as I explore in my copyediting and AI manifesto). However, the traditional notion of plagiarism – where one author uses another author’s text without credit – is still very much relevant. It’s this long-established form of plagiarism that I’ll discuss here.

Authors and publishers should be aware of the law and ethical standards, both to protect their reputation and to avoid prosecution.

Editors and proofreaders aren’t usually responsible for identifying plagiarism. However, the reality is that they often do, thanks to their sensitive linguistic palate and under-the-hood technical knowledge of word-processing software (as we’ll see below).

Why do authors plagiarize?

As editors Vee White and Andrea Klinger explored in their international study, plagiarism isn’t always deliberate.

Sometimes it might result from an author’s genuine ignorance of the rules and conventions surrounding the reproduction of others’ work. Sometimes it might be a shortcut (e.g. if an author is commissioned to write in a language other than their own and doesn’t feel confident formulating their own words). Sometimes it is intended as a mark of respect (in some cultures, repeating another author's words verbatim is a way of honouring them).

And, even when plagiarism is deliberate, the culprit isn’t necessarily sat rubbing their hands together with Machiavellian glee. They might instead have been desperately chasing a deadline or buckling under pressure from their organization or those around them. (This isn’t intended to excuse plagiarism – ultimately, it’s always theft – but it is important to remember that there may be a well-meaning but deeply stressed or deadline-hounded human behind a case of plagiarism, and that person may be owed a duty of care. More on this below.)

What is plagiarism?

Plagiarism is the reproduction without credit or permission of material (text or images) previously published elsewhere in such a way that the material appears to be one’s own. It applies to material of any length, even a few words, and it encompasses ideas as well as actual words.

This definition includes ‘self-plagiarism’, or the reproduction of one’s own material. If you want to reuse your own text and you published it via someone else (e.g. in a book or on your organization’s website), you should always check with the ‘someone else’ first (or consult your contract, if applicable) in case there are legal restrictions.

It’s commonly said that it’s unlikely any two authors will write the same seven words in exactly the same order. So, if the same sequence of seven words appears in two separate publications, it’s a strong clue that there might be plagiarism at play.

How to avoid plagiarism

The basic rule is that, if an author wants to use text that has previously been published (even in a more informal format such as a blog post), it must be put within quote marks and credit must be given to the original author. Credit usually takes the form of a citation and reference (in a book or article) or perhaps a hyperlink to the original material (in online content). I have lots more guidance on how to do this in my post on how to verify and cite quotations.

Additionally, it’s not acceptable to re-use text but change a few words here and there to make it different from the original.

If you want to cite or refer to your own material, it’s standard practice (particularly in academic writing) to quote yourself just as you would any other author. Alternatively, if you want to avoid doing that, rewrite the material afresh.

Another point to consider is that, even when text has been correctly placed in quote marks and credited to its original author, it may still be necessary to seek permission from the copyright holder. This is a separate issue. Gillian Davies’ book Copyright Law for Writers, Editors and Publishers (A & C Black, 2011) is a useful guide to the issues surrounding copyright (and it has some helpful content on plagiarism too).

Is it the editor’s responsibility to find plagiarism?

In short, no.

Unless specifically contracted otherwise and provided with appropriate tools to do so, copyeditors and proofreaders cannot generally be expected to identify plagiarism. It is often invisible, and plagiarism checkers can be unreliable and usually have word limits.

However, there are certain clues editors can look for to help them identify plagiarism. When they spot it, they should report it to their client immediately (or discuss it with the author, if the author is also the client).

The Chartered Institute of Editing and Proofreading’s Professional Practice Code explains this perfectly:

Since the supplier [i.e. the editor] is responsible neither for commissioning work nor for contracting with an author, the supplier cannot be held responsible for questionable material (whether factual or otherwise) or material where possible legal problems (for example, libel, infringement of copyright, plagiarism) may arise. However, a supplier becoming aware of any such problems in the material should bring these to the attention of the client. Any duty the supplier has to the client will be fully discharged by this process, and the client, while they may be guided or advised by the supplier, bears the whole responsibility for deciding what is to be done in these cases.

Chartered Institute of Editing and Proofreading, Professional Practice Code, 5.3.2c

How to spot plagiarism

All of the issues below can be and almost always are innocuous authorial errors that have nothing to do with plagiarism. However, particularly prominent or repeated issues, or several of these issues in combination, might mean it’s worth digging deeper.

1. From the prosaic to the sublime (or vice versa)

A sure clue is when an author’s writing style suddenly changes mid-way through their piece. This might be a switch in tone (such as informal to formal), or it might be a jump from messy English to a more polished style. There are all sorts of possibilities, and they can be subtle. My post on authorial voice might give you some ideas on what to look out for.

2. Ambiguous nationality

Different languages and regions of the world have different spelling and punctuation conventions (as I’ve explored in my post about why I use -ize spellings on my website). If a text starts out by writing consistently in UK-style English and suddenly switches to US style (for example), it might be a sign part of it has been copied from elsewhere.

3. Contrary referencing

A manuscript will often quite naturally contain a variety of referencing styles – for example, if an author was in a rush or is unfamiliar with the rigours of formal referencing. However, consistent inconsistencies – where, rather than a hodgepodge of styles, there are discrete groups of references each with their own perfectly implemented style – may be a sign to take a closer look.

4. Disjunctions in content

Paragraphs that appear to have been stuck together with little continuity of argument might contain content that’s been ‘borrowed’ from elsewhere.

5. Erratic styles

In addition to editing the actual text, editors are often asked to standardize the underlying styles in a piece of work (a ‘style’ in Microsoft Word is a set of characteristics, such as font, size and colour, that is applied to text). Sometimes, the process of applying styles reveals that what initially appeared to be all in the same format actually contains multiple styles. This may be a sign that text has been copy-pasted from another digital source (bringing with it the original source’s style).

Plagiarism checkers and tools

If I suspect something isn’t quite as it should be in a document, I always start by simply pasting a sentence or two into Google. I put double quotes around the text so that Google looks for that exact string of words.

Alternatively, when I need to check a longer section of text, I’ll try one or more plagiarism tools. I’m deliberately not mentioning any single provider because these tools aren’t fully reliable and they often yield different results. Using two or three means I get a better picture of how likely it is that the text contains plagiarism. Three positives? Probably something to investigate. But one positive? Perhaps I’ll make a note but keep editing for a while and see if any other potential passages jump out at me.

If I suspect plagiarism, I tend to use one or both of these methods to perform quick-and-dirty checks. If I find anything, I then send the material back to my client for them to investigate further, or, if the author is my client, I carefully broach the subject with them.

Prioritizing tact around plagiarism

One final – and vital – point is that editors and proofreaders should always be extremely careful raising issues surrounding plagiarism. Especially in academia, it is taken very seriously, and it can affect authors’ whole careers. Even when you have a case of plagiarism that seems so obvious the author may as well have tied a red bow around it, raise the issue with great care. You probably don’t have the full picture and your instincts might be wrong. And the author may be genuinely ignorant that what they have done is not acceptable (I have identified several instances of plagiarism where this was the case).

Keep all communications on a need-to-know basis. I start by picking the most appropriate person to contact (not the author, unless the author is also the client) and asking them to verify my suspicions. Never fire off a round robin to the whole project team. Doing so may only lead to unnecessary embarrassment for the author (or you, if your suspicions turn out to be incorrect – for example, if the ‘plagiarism’ is an authorized reproduction but your contact forgot to let you know about it).

I’ve seen a number of problems arising from both unwitting and more malicious plagiarism: projects delayed, time wasted, authors upset, even entire chapters pulled. Eagle-eyed editors can save their clients and authors much hassle and heartache by learning the signs of plagiarism and reporting potential cases with sensitivity.