It's important to cite sources you used in your research for several reasons:
You must cite:
When in doubt, be safe and cite your source!
Citing a source means that you show, within the body of your text, that you took words, ideas, figures, images, etc. from another place.
Citations are a short way to uniquely identify a published work (e.g. book, article, chapter, web site). They are found in bibliographies and reference lists and are also collected in article and book databases.
Citations consist of standard elements, and contain all the information necessary to identify and track down publications, including:
Here is an example:
Snyder, C.R. & Shorey, H.S. (2002). Hope and academic success in college. Journal of Educational Psychology, 94 (4), 820.
Citations may look different, depending on what is being cited and which style was used to create them.
Plagiarism occurs when you borrow another's words (or ideas) and do not acknowledge that you have done so. In this culture, we consider our words and ideas intellectual property; like a car or any other possession, we believe our words belong to us and cannot be used without our permission.
Plagiarism is a very serious offense. If it is found that you have plagiarized -- deliberately or inadvertently -- you may face serious consequences. In some instances, plagiarism has meant that students have had to leave the institutions where they were studying.
The best way to avoid plagiarism is to cite your sources - both within the body of your paper and in a bibliography of sources you used at the end of your paper.
Some useful links about plagiarism: