Plagiarism is one of the most serious academic offences — and one of the most preventable. This guide explains the different types, how detection tools work, the rules for quoting and paraphrasing, and practical strategies that protect your work.
Plagiarism is presenting someone else's work, ideas, data, or words as your own — without giving them credit. In academic writing, this includes using text without quotation marks, paraphrasing too closely without a citation, submitting someone else's code as your own, or reusing your own previously submitted work without permission (self-plagiarism).
Plagiarism can be intentional (deliberate copying) or unintentional (poor paraphrasing, forgotten citation, careless note-taking). Universities treat both seriously — intent affects the penalty, but not whether a violation occurred.
Consequences range from a zero on the assignment to permanent expulsion, damage to your professional reputation, and in published research, formal retraction. None of these are recoverable in the short term.
| Type | What It Looks Like | Severity |
|---|---|---|
| Direct / verbatim copying | Copying text word-for-word without quotation marks or citation | High |
| Mosaic / patchwork plagiarism | Mixing source words with your own, swapping synonyms, but keeping the structure | High |
| Paraphrase without citation | Rewriting someone's idea in your own words but not citing the source | Medium–High |
| Self-plagiarism | Submitting your own previously submitted work to another course without permission | Medium–High |
| Incorrect citation | Citing a source that does not say what you claim it says | Medium |
| Accidental omission | Forgetting to add a citation to a note that got copied into a draft | Low–Medium |
Understanding the difference between these three techniques — and when to use each — is the foundation of academic integrity.
Use when the exact wording matters — a technical definition, a memorable formulation, a critical statement you want to analyse closely. Keep quotations short and purposeful. In STEM writing, direct quotes are rarer than in humanities — you more often paraphrase data and findings.
Paraphrasing means expressing someone else's idea in your own words and sentence structure. The idea is still theirs — a citation is still required. Poor paraphrasing (changing only a few words) is the most common form of unintentional plagiarism.
The model they proposed reached a diagnostic accuracy of 97.3% on the validation set, surpassing all benchmarks previously reported (Chen et al., 2023).
Chen et al. (2023) demonstrated that their diagnostic model exceeded all existing benchmarks, with validation accuracy surpassing 97%.
Summarising condenses a longer section — a paper, chapter, or argument — into a few sentences. You capture the key points without the detail. Like paraphrasing, a citation is always required even though none of the original wording is used.
Our specialists write from scratch — no recycled content, no plagiarism, full reference list included.
A common source of confusion: do you need to cite everything? No — but you need to cite more than most students initially assume.
| Needs a citation | Does NOT need a citation |
|---|---|
| Direct quotes from any source | Your own original analysis and conclusions |
| Paraphrased ideas from a source | Common knowledge (water boils at 100°C) |
| Data, statistics, and figures from others | Established definitions in standard textbooks |
| Tables, charts, and images from others | Your own original experimental data |
| Methods adapted from published papers | Mathematical proofs that are clearly standard |
| Software tools and datasets | Lab procedures from your course manual |
When in doubt, cite. An unnecessary citation costs you nothing. A missing citation on someone else's idea is plagiarism. The safe default is always to add the reference.
Most universities use Turnitin, iThenticate, or similar tools. Understanding what they detect helps you interpret your similarity score correctly.
Good similarity scores: a typical well-cited STEM paper will score 10–25% due to quoted material and reference lists. Above 30–35% warrants review. But the number is a prompt to review, not a verdict — context matters.
Self-plagiarism (also called "recycling" or "duplicate submission") is submitting your own previously graded work, in whole or in part, to satisfy a different assignment — without permission from both instructors.
Why it is a problem: each assignment should represent new original work completed for that course. Reusing your own content gives you an unfair advantage over students who completed fresh work, and it misrepresents the scope of your effort.
What is allowed:
What is not allowed without explicit permission:
Plagiarism in STEM is not limited to text. Copied code, fabricated data, and undisclosed collaboration are all forms of academic dishonesty:
Yes, always. The idea, finding, or data still belongs to the original author — paraphrasing changes the wording but not the intellectual ownership. A citation is required every time you use someone else's idea, regardless of whether you use their exact words.
Not necessarily. Open the similarity report and review what is flagged. If the matches are your reference list, properly quoted and attributed passages, or common phrases, they are not plagiarism. If a flagged passage closely matches a source without a citation, that is the problem — fix the citation, not just the wording.
You should always read what you cite. If you cannot access the original source, you can use a secondary citation — "as cited in Chen et al. (2023)" — but this should be rare. Secondary citations are weaker evidence because you are relying on someone else's interpretation of the original.
Plagiarism is passing off someone else's work as your own. Collusion is working with others on an individual assignment (or sharing your work for others to copy) without permission. Both violate academic integrity policies. Collusion includes sharing draft essays, dividing up answers in an individual assignment, or using AI tools in ways your institution prohibits.
This depends entirely on your institution's policy, which varies widely and is evolving. Submitting AI-generated text without disclosure is increasingly treated as a form of academic dishonesty — misrepresenting the source of your work — even if it does not match any existing source. Always check your university's AI usage policy before using generative AI tools in assessed work.