I Didn’t Copy Anything, So Why Is My Plagiarism High? The Writing Mistakes Students Don’t Notice

Whenever the issue of accidental plagiarism comes up, I always remember an incident that happened in a colleague's office. I had visited this colleague, and two students she was supervising came to the office to submit their dissertation draft. Once they had submitted the drafts, I glanced through them, and they were outstanding work. I asked them whether they had copied from somewhere, and they replied, 'No!' Unfortunately, my colleague remembered she had to run a Turnitin check for them.

We asked them to submit their soft copy, and we ran the Turnitin score; the first guy had 35%, and the second had exactly 20%. The room was silent for a while until my colleague said, "Ah, well, you copied then." The guy who had 35% sat on a chair there, and his face showed he was expecting that. We asked him where he copied from, and he said he didn't, but then he knew his family members would add some to it.

My colleague didn't understand at first until I asked the student again, "So you mean witches from your family increased the score?" He said, "Yes!" Then we started laughing. We thought he was finding an excuse, but the student was very serious. No matter what we said, he insisted it was his grandmother who did that at night, because he didn't copy from anywhere. At the end, it was turning into tears, so we went outside, laughed for a while, came back, and asked them to go. After they left, I reviewed the student who got 35%'s work and realised he repeated the mistakes I am about to discuss.

Why Your Plagiarism Score is High 

Every semester, you will hear the same complaint echoing through campuses and inWhatsApp groups.

“I didn’t copy anything, but my plagiarism is high.”

If you are a student, you have probably said it yourself or heard a friend say it. You write your work carefully, you try your best to avoid copying and pasting, and still, the plagiarism report looks scary. At that moment, frustration sets in. You feel misunderstood, even punished unfairly.

The truth is simple, though uncomfortable. High plagiarism does not always come from cheating or from your "grandmother". Sometimes, it comes from writing mistakes that a student does not even realise he or she is making.

Let me walk you through the most common ones.

Repeating Full Terms Instead of Using Short Forms

Many students do not know this, but plagiarism software does not understand the meaning of just the word you used. It recognises patterns of words. When you keep repeating long academic terms exactly as they appear in books and articles, the similarity score will also increase.

For example, if you keep writing "Resource-Based View" throughout your work without shortening it (RBV), you are repeating the same phrase that appears in hundreds of published papers. The same applies to "organisational citizenship behaviour" (OCB) or "Human Resource Management" (HRM).

Smart academic writing introduces the full term once, then uses the short form. You write the "Resource-Based View (RBV)" at the beginning, and afterward you use "RBV". This small habit reduces unnecessary repetition and lowers similarity scores naturally. It also shows maturity in academic writing. Lecturers notice that.

Including Preliminary Pages and Appendices in Plagiarism Checks

Another silent mistake is submitting everything for plagiarism checking. Title pages, declarations, tables of contents, and appendices often contain standard wording. These sections are similar across many students’ works, so they automatically increase similarity.

When a student includes them in the plagiarism report, the software does exactly what it is designed to do. It flags matching text.

This is why many lecturers ask for plagiarism checks on specific chapters only, usually the introduction, literature review, methodology, and discussion. If you are unsure, ask. Submitting everything blindly only works against you.

You may not have copied anything, but the system does not care about intention. It only sees text.

Making Claims Without Citing Sources

This is one of the most misunderstood causes of high plagiarism. Students sometimes write strong statements that sound academic but forget to cite where the idea came from.

When you make a claim that already exists in literature and fail to cite it, plagiarism software compares your sentence with existing work. If it finds similar wording elsewhere, the similarity score will go up.

Quotations are even more dangerous when they are not cited. Even if you put quotation marks, failing to acknowledge the source still counts as poor academic practice, and Turnitin will flag it as plagiarized. 

Proper citation does two things. It protects you from accusations of plagiarism, and it strengthens your work. You are not just giving opinions. You are standing on evidence.

So, in the end, what do we mean?

High plagiarism does not always mean dishonesty. Often, it means poor writing habits. Once you understand how plagiarism systems work, you stop fighting them and start working with them.

If you genuinely did not copy, then fix the writing mistakes. Your score will reflect the effort you put in.