Depending on the purpose a source plays in your writing, you will offer your reader more or less information about the author, context, and specific language. There are three ways to incorporate a source’s ideas into your writing: quotation, paraphrase, and summary.
reproduces the author’s exact language, word for word, within quotation marks.
Reproduces author’s idea and argument in about the same amount of space as the original, but in your own words and your own sentence structure.
Represents an overall argument in a much more compact space in your own words.
Contrary to popular belief, overusing quotations suggests to your reader that you have not really understood what you have read, and that you have simply copied material to make it seem as if you have read carefully.
Generally in the sciences and social sciences, paraphrases and summaries are preferred, though a quotation of a few words is useful for borrowing particularly apt phrasing or technical language. In the humanities, quotations are more welcome, particularly when the actual words of the writer are important to your argument (such as in philosophy, where entire arguments can turn on the use of one word over another).
In any case, do not overuse quotations by quoting either very long or numerous passages. A good summary or paraphrase is often more effective than a quotation to demonstrate to your readers that you have a good grasp of the material you have read.
As students you present your results and ideas through writing; it is crucial that you respect the work of others by learning to paraphrase and summarize correctly, without misrepresenting either the ideas or the writing of others as your own.
Students often assume that paraphrasing means “changing enough words” to avoid plagiarism. But this precisely the wrong approach. If you ask “have I changed the source enough to avoid plagiarism?” you have misunderstood the point of using sources. The point of paraphrasing is to explain another person’s ideas clearly to your reader. Instead of making changes in the original sentence until you are not plagiarizing, begin by closing your book and writing what you understand the source to be saying. This strategy also ensures that, when you paraphrase and summarize, you actually understand the ideas you are using, which is the whole point of the exercise.
For more on correctly constructing and formatting quotations, paraphrases and summaries, consult A Writer’s Reference under sections MLA-2 (p. 331), APA-2 (p. 383), and CMS-2 (p. 419).