All 12 examples at a glance
Plagiarism is presenting someone else’s words, ideas or work as your own. The table lists the twelve examples on this page and the fix for each. Every source, author and name in the examples is invented for this guide.
| Example | What the student did | The fix |
|---|---|---|
| 1. Direct copy | Pasted a passage with no quotation marks and no citation. | Quote and cite it, or paraphrase and cite it. |
| 2. Missing quotation marks | Copied the exact words and added a citation only. | Add quotation marks and the page number. |
| 3. Mosaic | Blended the author’s phrases into their own sentences. | Quote the phrases, or rewrite the passage. Cite it. |
| 4. Paraphrase, no citation | Restated the idea in new words and gave no source. | Add the citation. |
| 5. Paraphrase too close | Kept the author’s sentence and swapped a few words. | Write it again in your own structure. Cite it. |
| 6. Self-plagiarism | Reused part of an essay already handed in. | Ask permission and cite the earlier essay, or write new text. |
| 7. Wrong source | Cited a study they never read and left out the page they did read. | Read the study, or cite it as found in the source you read. |
| 8. Invented source | Made up a reference to support a claim. | Find a real source or remove the claim. |
| 9. Undisclosed AI text | Handed in AI-generated text where the course requires disclosure. | Write it yourself, or disclose and cite as the course requires. |
| 10. Image | Used a photo with no credit. | Add a caption with the creator and source. |
| 11. Data | Turned someone’s figures into a chart with no source. | Name the data source under the chart. |
| 12. Code | Pasted a function from a forum and renamed the variables. | Credit the author in a comment, if outside code is allowed. |
For definitions of each kind, see our guide to the types of plagiarism.
Copied words: examples 1 to 3
In these three cases the student uses the author’s exact words. University example pages, such as the ones from Bowdoin College, focus on this group, because it is the easiest to show side by side.
Example 1: direct copy
Original. “Coral reefs cover a tiny part of the sea floor, yet a large share of all sea life depends on them at some stage. When a reef dies, the fish that feed and breed there leave or die with it.” (Marchetti, 2020, p. 31)
Student version. Coral reefs cover a tiny part of the sea floor, yet a large share of all sea life depends on them at some stage. When a reef dies, the fish that feed and breed there leave or die with it.
Why it is plagiarism. The passage is copied word for word. There are no quotation marks and no citation, so the reader thinks the student wrote it. This is direct plagiarism.
Fixed version. Reefs matter far more than their size suggests. Marchetti (2020) points out that much of the life in the sea relies on a reef at some point, so losing one reef also means losing the fish that use it (p. 31).
Example 2: exact words with a citation but no quotation marks
Original. “A deadline does not create motivation; it only moves it to the last possible moment.” (Abara, 2019, p. 7)
Student version. A deadline does not create motivation; it only moves it to the last possible moment (Abara, 2019).
Why it is plagiarism. The citation credits the idea. Without quotation marks, the sentence still tells the reader that the wording is the student’s. It is not.
Fixed version. As Abara (2019) puts it, “a deadline does not create motivation; it only moves it to the last possible moment” (p. 7).
Example 3: mosaic plagiarism
Original. “Night-shift workers sleep less and sleep worse than day workers, because daylight and household noise interrupt the rest they try to take in the morning.” (Dvorak, 2021, p. 112)
Student version. People on night shifts often struggle, since they sleep less and sleep worse than day workers. The main cause is that daylight and household noise interrupt the rest they need (Dvorak, 2021).
Why it is plagiarism. The highlighted phrases are the author’s exact words, mixed into the student’s sentences without quotation marks. A citation is there, but it does not mark which words were borrowed.
Fixed version. Dvorak (2021) links the poor sleep of night-shift staff to their schedule: they have to rest in the morning, when light and a busy home keep waking them (p. 112).
More on example 3 in our guide to mosaic plagiarism.
Paraphrases: examples 4 and 5
A paraphrase needs two things: your own wording and a citation. Each example below is missing one of them. The Northern Illinois University tutorial lists “Paraphrasing without Citing” as its own category of plagiarism.
Example 4: paraphrase without a citation
Original. “Children who are read to every day start school knowing far more words than children who are not, and the gap is still visible years later.” (Halloran, 2018, p. 64)
Student version. Daily reading at home gives children a much bigger vocabulary by the time they start school. This early advantage lasts for years.
Why it is plagiarism. The wording is the student’s own, but the finding is Halloran’s. With no citation, the student presents someone else’s research as their own knowledge.
Fixed version. Daily reading at home gives children a much bigger vocabulary by the time they start school, and Halloran (2018) found that this early advantage lasts for years (p. 64).
Example 5: paraphrase too close to the original
Original. “Remote workers save time on commuting, but many report that the boundary between work and home becomes harder to keep.” (Sato, 2022, p. 9)
Student version. Remote employees save time on travelling, but many say that the border between job and home becomes more difficult to maintain (Sato, 2022).
Why it is plagiarism. This is the author’s sentence with synonyms swapped in. The order of ideas and the sentence pattern are unchanged. A citation does not fix it, because the wording is still not the student’s. This is often called patchwriting.
Fixed version. Working from home removes the commute. Sato (2022) notes that it has a cost too: many people find that work spills into their home life (p. 9).
Where exactly the line is: is paraphrasing plagiarism? For the method, see how to paraphrase without plagiarizing.
Self-plagiarism: example 6
You can plagiarize your own work. The MLA Style Center says “it’s even possible to plagiarize yourself” when you reuse earlier ideas or phrases without citing the earlier work.
Example 6: reusing an old essay
Original. A paragraph from the student’s own sociology essay, handed in last semester: “Social media rewards quick reactions, which leaves little room for careful argument.”
Student version. The same paragraph, pasted into a new essay for a media studies course this semester. The earlier essay is not mentioned.
Why it is plagiarism. The work was already graded once. Handing it in again presents old work as new work written for this course. Most courses require new work unless the instructor agrees to reuse.
Fixed version. Ask the instructor first. If reuse is allowed, cite the earlier essay: “As I argued in an earlier essay (Okonkwo, 2025), social media rewards quick reactions.” If it is not allowed, write a new paragraph.
See our guide to self-plagiarism for the rules on reusing your own work.
Wrong or invented sources: examples 7 and 8
Here the problem is the citation itself. Some policies list these cases under plagiarism. Others call them fabrication or falsification. Either way they break academic integrity rules.
Example 7: citing a source you did not read
Original. The student read a blog post by Pell (2024). The post sums up a study by Nakamura (2016) on short breaks and concentration.
Student version. “Nakamura (2016) found that short breaks improve concentration.” Only Nakamura is in the reference list. The student never opened the study.
Why it is plagiarism. The citation tells the reader that the student read Nakamura’s study. They did not. The summary is Pell’s work, and Pell gets no credit. If Pell described the study wrongly, the student repeats the error under Nakamura’s name.
Fixed version. Find and read the study, then cite it. If you cannot get it, cite what you read. In APA style: “Short breaks improve concentration (Nakamura, 2016, as cited in Pell, 2024).” Only Pell goes in the reference list.
Example 8: an invented reference
Original. There is none. The student half remembers a number from a lecture and cannot find where it came from.
Student version. “More than 70% of students prefer printed textbooks (Greene, 2021).” No such source exists. The student made up the reference to fill the gap.
Why it is plagiarism. A made-up source misleads the reader about where a claim comes from. It is fabrication, and many institutions treat it as more serious than a missing citation.
Fixed version. Look for a real source and report what it actually says, with a correct citation. If you cannot find one, remove the claim. Check every reference an AI tool gives you too, because these tools can produce references that do not exist.
The citation generator formats in-text citations and reference entries once you have the real source details.
Undisclosed AI text: example 9
Rules on AI tools differ between courses. This example assumes a course that requires you to disclose any AI use.
Example 9: AI text where the course requires disclosure
Original. The course policy says: “AI tools may be used for brainstorming. Any other use must be disclosed.” The student asks an AI chatbot to write a paragraph on the causes of inflation.
Student version. The AI paragraph, pasted into the essay as written. There is no note about AI use and no citation.
Why it is plagiarism. The student presents text they did not write as their own and breaks the disclosure rule. Depending on the policy, this is called plagiarism, unauthorized assistance or academic misconduct.
Fixed version. Write the paragraph yourself from your course readings and cite them. If the course allows AI-generated text, disclose it in the way the policy asks and cite the tool.
More detail: is using AI plagiarism? and how to cite ChatGPT.
Images, data and code: examples 10 to 12
Plagiarism is not limited to sentences. The Northern Illinois University tutorial also lists “Plagiarism in Graphs”: using graphs, charts, figures or images from a source without citing it.
Example 10: an image without credit
Original. A photo of a glacier on a photographer’s website. The photographer is Ines Varga.
Student version. The photo appears on slide 3 of a presentation. There is no caption, or the caption says only “Source: internet”.
Why it is plagiarism. Someone else made the image. With no credit, the audience assumes the student took it or that it belongs to no one. A search engine is not a source.
Fixed version. Add a caption that names the creator, title, year and where you found it, for example: “Glacier at dawn, by Ines Varga, 2022, inesvarga.example.” Also check that you are allowed to use the image. Credit and permission are two separate things.
Example 11: data without a source
Original. Table 2 in the Northfield Transport Survey (2023), showing bus trips per year.
Student version. A bar chart built from the same figures and labeled “Figure 1. Bus trips per year”. No source is given.
Why it is plagiarism. The student drew the chart, but did not collect the numbers. Without a source, the data look like the student’s own research.
Fixed version. “Figure 1. Bus trips per year. Data from Northfield Transport Survey (2023, Table 2).” Add the survey to the reference list.
Example 12: code without credit
Original. A 12-line sorting function posted in a public forum answer by a user called tidewater_dev.
Student version. The same function in a programming assignment, with the variable names changed and no comment about where it came from.
Why it is plagiarism. Renaming variables does not make the logic the student’s own. The grader will assume the student wrote the function. Many courses also limit how much outside code is allowed.
Fixed version. First check that the course allows outside code. If it does, add a comment above the function: “Adapted from a forum answer by tidewater_dev”, with the link and the date you accessed it.
For captions and reference entries, see how to cite an image.
Three examples that look like plagiarism but are not
Not everything without a citation is plagiarism, and not every match in a report is a problem.
Common knowledge
Student version. “The Second World War ended in 1945.” “Water boils at 100 °C at sea level.” Neither sentence has a citation.
Why it is not plagiarism. These are facts that are widely known and easy to check in many places. They do not belong to one author, so they need no citation. Be careful with the limit, though. An author’s interpretation of a fact, a statistic or a recent finding is not common knowledge.
The UNC Writing Center suggests a simple test: ask yourself whether you knew the information before you took the course. If not, cite it. Its rule of thumb is “When in doubt, give a citation.”
Properly quoted and cited text
Student version. As Abara (2019) puts it, “a deadline does not create motivation; it only moves it to the last possible moment” (p. 7).
Why it is not plagiarism. The words are copied exactly, but the quotation marks show whose words they are and the citation shows where they come from. A plagiarism checker may still highlight the sentence, because it matches the source. That match is expected and needs no fix.
Your own ideas
Student version. “In my view, the school’s phone ban will not work, because it does not cover break times.” The student reached this view by reading the school’s policy and thinking about it.
Why it is not plagiarism. Your own argument, opinion, observation or results from your own survey or experiment need no citation. They are your work. Two limits apply: cite any source the idea builds on, and do not reuse work you already handed in elsewhere (see example 6).
Check your own work
Most of the examples above happen by mistake. A quote loses its quotation marks in your notes, or a citation is left for later and forgotten. See our guide to accidental plagiarism for the habits that prevent this.
Before you submit, go through your draft once with these questions.
- Are all copied words in quotation marks? Examples 1 to 3.
- Does every idea from a source have a citation next to it? Examples 4 and 5.
- Is everything new for this course? Example 6.
- Did I read every source I cite, and does each one exist? Examples 7 and 8.
- Did I follow the course rules on AI tools? Example 9.
- Do my images, charts and code name their makers? Examples 10 to 12.
A plagiarism check helps with the first question and part of the second. The Plagiarism Checker Plus plagiarism checker highlights each matching passage and links it to its source, so you can see what to quote, cite or rewrite. It compares wording, so it cannot see a missing citation on an idea you put fully in your own words, an invented source, or an uncredited image. Those you have to check yourself.