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Plagiarism

Similarity and Plagiarism — What's The Difference?

What’s the difference between similarity and plagiarism? Compare the meanings of similarity and plagiarism in this guide.

While reviewing writing and checking for plagiarism, you may have come across the term, “Similarity Index.”

What’s the similarity index refer to? Is there a difference between similarity and plagiarism? Where does one end and the other begin? 

In this article, we’ll take a closer look at both similarity and plagiarism to help you better understand their key differences, along with plenty of examples to illustrate.

What Is Similarity?

Similar ideas or concepts being shared, especially in specific industries, are commonplace and may not necessarily indicate plagiarism. 

Technical jargon and industry-specific expressions (think expressions like “cutting-edge technology”) are incredibly commonplace and shared across many fields or industries.

Similarity often happens when a discussion on a topic overlaps with existing material

How the similarity index is defined in academic journals

“Similarity and Plagiarism in Scholarly Journal Submissions: Bringing Clarity to the Concept for Authors, Reviewers and Editors,” an article available through the National Library of Medicine, offers the following definition of the similarity index:

the extent of overlap or match between an author's work compared to other existing sources (books, websites, student thesis, and research articles) in the databases of similarity checking tools.” - Similarity and Plagiarism in Scholarly Journal Submissions

So, essentially similarity (or the similarity index) describes when text (such as two different articles, papers, or blog posts on the same topic) overlap in terms of their ideas or concepts. 

Example: In the context of how to solve the issue of plagiarism, two authors may talk about the use of AI to identify instances of plagiarism in a similar way, with research that was conducted independently.

What’s happening is that the two works are likely pulling information from the same studies, articles, or research available, while using similar terms and ideas to reference and cite the material

The similarity index: acceptable similarity levels in journals

Plagiarism detection software may flag similarities based on how much one passage or text matches another existing publication. 

The level or percentage of similarity that’s acceptable in academic work varies. 

For instance, according to “Similarity and Plagiarism in Scholarly Journal Submissions,” some journal editors accept submissions that have 5% (or lower) similarity, while others may turn away submissions with a similarity level above 10%

The key takeaway? The acceptable level of similarity is dependent on the editorial policies of a particular publication

It’s best practice to review publication guidelines before submitting work.

How Do Similarity and Plagiarism Differ?

A look at the definition of plagiarism

In contrast to similarity which describes overlap, plagiarism, is when someone directly copies another person’s work and tries to pass it off or take credit for it as their own original idea.

The above-mentioned journal article defines plagiarism as:

when somebody presents the published or unpublished work of others, including ideas, scholarly text, images, research design and data, as new and original rather than crediting the existing source of it.” - Similarity and Plagiarism in Scholarly Journal Submissions

There are several types of plagiarism, here’s a quick overview of two common kinds of plagiarism:

Direct Plagiarism

Copying and pasting entire sentences, paragraphs, or other sections of text directly from one piece into your own work without proper citation or credit is direct plagiarism

When you reference another author’s work, conclusion, or study, you must cite them and give credit where it’s due (learn more about citation checkers). 

Paraphrasing

Paraphrasing involves swapping out a few words from a source and editing them just slightly so that the quote or reference isn’t a word-for-word copy of the original. In the case of paraphrase plagiarism, the original author or source isn’t acknowledged with proper citations. 

The Originality.ai plagiarism checker is an excellent way to check for more complex kinds of plagiarism like paraphrase plagiarism. 

Plagiarism from a legal or ethical standpoint

Plagiarism holds the potential for legal and ethical implications:

The best practice is to properly cite any sources included in a work.

Similarity vs. plagiarism when it comes to intent

One of the main differences between similarity and plagiarism has to do with intent; in other words, what’s driving the action

Intent in the context of similarity

If two or more people are working on a given topic in a given industry, some overlap may occur. 

The difference? Each person is conducting independent research on a similar topic and providing citations where they reference the research of others. 

Intent in the context of plagiarism

With plagiarism, the intent may be to present the work of another author as theirs without proper credit.

It’s important to note that accidental plagiarism does occur. For instance, a person might forget citations or improperly reference a quote within the text. This is where plagiarism checkers come in especially handy. 

With a plagiarism checker, you can review text and check any highlights to make sure quotes are properly cited before submitting work.

How Are Works Cited if They Deal With Similar Topics?

With plagiarism, the plagiarized work is not correctly cited; that’s one of the factors that makes it plagiarism to begin with. 

Remember, it’s not enough just to change a few words around or sprinkle in a handful of synonyms — you still have to credit the original author

With similarity, works are typically correctly cited. 

Two articles can be about similar topics and even pull the same quotes from researchers and studies or other experts, as long as they’re cited. 

When you correctly reference the author as the origin of a quote, study, or other piece of information you’re including, you help to avoid plagiarism.

Final Thoughts: Similarity vs. Plagiarism

Similarity occurs when two distinct papers or articles cover the same topic. They may reference the same studies, charts, or experts, but the research is independent and cited properly. In short, the similarity is in the data, not the argument or interpretation itself. 

In contrast, plagiarism uses someone else’s work and passes it off as theirs without referencing the original author. It misrepresents the origins of work and can have serious consequences. 

To identify potential instances of plagiarism or quotes that need citations, complement your editing process with a plagiarism checker. Carefully review highlights to ensure that the research conducted for the piece correctly references the original author(s).

Referencing the original author or study helps to avoid and prevent plagiarism and establish credibility as a thought leader in your space. 

Learn more about plagiarism in our top guides:

Sherice Jacob

Sherice Jacob is a seasoned copywriter and content professional fluent in English, Spanish, and Catalan, with over 25 years of experience crafting high-converting copy. Passionate about AI, she enjoys exploring the new innovations and possibilities it brings to the world of content creation.

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