Plagiarism refers to presenting someone else’s words, ideas, or expressions as one’s own original work. Although definitions differ by institution and culture, it is widely regarded as a breach of ethical standards in education, research, and journalism. It is closely connected to ideas of ownership, responsibility, and reputation, and attitudes towards it vary across cultures. While it is most commonly discussed in relation to written work, plagiarism applies to ideas themselves, regardless of how they are expressed—whether through speech, writing, or artistic creation. In academic settings, plagiarism is treated especially seriously because it threatens personal credibility as well as the reputation of institutions, journals, and entire fields of study.

As a result, universities and research organisations enforce academic integrity policies to discourage and penalise it. Consequences can include academic penalties, loss of employment, or other sanctions.

Technological developments have made plagiarism easier to commit but also easier to detect. More recently, tools such as large language models including ChatGPT, have sparked debate about authorship, originality, and responsibility.

Not all societies share the same views on intellectual ownership, and plagiarism itself is not always a criminal offence. However, it can overlap with legal issues such as copyright infringement, fraud, or violations of moral rights. Even when it does not break the law, plagiarism remains a serious ethical violation because it involves misrepresenting another’s work as one’s own work.

Types of Plagiarism Some types of plagiarism include:

Deliberate plagiarism, i.e., intentionally using someone else’s work or portions of other people’s work and claiming it as one’s own

Accidental plagiarism, i.e., unintentionally using someone’s work due to insufficient paraphrasing, poor note-taking, or memorisation, which mostly affects only a portion of one’s work

Self-plagiarism, i.e., copying or reusing one’s previous work without citing oneself, including recycling (submitting the same paper or assignment for different publications or classes) and global plagiarism (reusing someone else’s entire work and claiming it as one’s own, such as contract cheating and purloining, i.e., reusing someone’s work without permission)

Incremental plagiarism, i.e., using quotes without attributing them as such, usually due to insufficient note-making or forgetting to include the citation, which may also include sham paraphrasing, i.e., changing only a few words and nearly copying word-by-word