Understanding and Avoiding Plagiarism

What is plagiarism?

Caltech's honor code states:

"No member of the Caltech community shall take unfair advantage of any other member of the Caltech community."

Plagiarism is the appropriation of another person's ideas, processes, results, or words without giving approprate credit, and it violates the honor code in a fundamental way. One of the collective goals of Caltech is to produce new knowledge through research and writing, and we often do that work through collaboration. For this process to work, we need to be able to trust that when our ideas or words are taken up by another thinker, we will be credited for our contribution to his or her thinking. Not crediting the author of writing or ideas takes unfair advantage of the intellectual work that indivdual has done.

How do academic writers cite their sources? 

What it means to properly attribute ideas is culturally dependent, and American scholarly communities have very specific rules about how attribution works. The particulars vary by discipline and context, and many fields have developed elaborate systems for this purpose, such as MLA format in English, APA in Psychology, and CSE in some scientific writing. Here are the essential features of attribution that are present in every system:

  • In-text citation: Any time you borrow language or paraphrase ideas, processes, or results from another author--whether that writing/idea was published or unpublished, in print or online--you must make this clear within your text. This is usually done within the sentence itself, parenthetically, or with a footnote or endnote. Every citation system has a specific format for in-text citation.
  • References page: Every essay or document you produce that contains in-text citations should also have a references page, in which you present the complete bibliographic information for the cited texts. Again, each citation system handles the particulars differently (including having different names for what this part of a text is called), but it usually requires a list of texts that appears at the end of the document.

The results of properly done in-text citations and a references page are (1) that a reader ALWAYS knows without question or ambiguity which ideas and language were developed by you, and which come from other sources and (2) that a reader can easily locate that original source if he or she wants to follow up on your ideas. It takes careful notetaking, writing, and revision to accomplish this. Keep in mind that plagiarism isn't just about taking sentences from other writers; even if you change all the words by paraphrase, if the idea or finding comes from someone else, you are required to make that clear to your reader.

How do I know when to cite and when not to cite?

This question is more complex than it first appears. As a student writer, if you are not sure if you are required to cite a source, it is always better to err on the side of caution and cite; academic readers are  more tolerant of overcitation than undercitation. However, it's always ideal to consult an expert so you avoid both overcitation and undercitation.

Knowing what to cite depends on knowing your audience. Generally, it is not expected that writers cite ideas that are "common knowledge" for their audience. For example, physicists rarely cite Newton when employing his key concepts, because the audience for writing in this field is familiar with these concepts and already knows they began with Newton. When you are new to a field, however, it's very difficult to know what counts as common knowledge and what does not, and the answer to this question can shift depending on instructor preferences. For example, some instructors may expect you to carefully cite all sources in an essay, while others will find it appropriate for you not to cite work from the assigned reading, because the assumption is your audience (the professor) already knows where those ideas originate. If you are not sure where the line is between what should and should not be cited, ask your professor or TA for guidance.

Who can help me avoid plagiarism and cite sources correctly?

Your instructor and TAs are great resources for answering questions about what citation system to use and what the citation conventions are to be used for a particular assignment.

But if you need help with the implementation of a citation system, make an appointment with the Hixon Writing Center. We're glad to work with you on the sentence level to help you with this core feature of academic writing.

For more online resources related to citation, see our Resources page. You'll find links to up-to-date resources about the major scholarly citation systems.

For guidance in using a the citation management system Zotero, contact the Caltech Library.

What happens if part or all of an essay I submit to an instructor is plagiarized?

As stated above, plagiarism violates Caltech's honor code. As a result, cases of plagiarism are referred to the Board of Control for review.