Information from sources can be used to introduce an important concept, establish the strength of your argument, and elaborate on the central ideas in your document. Writers frequently state a point, offer a reason to accept it, and support their reasoning with evidence from a source, typically in the form of quotations, paraphrases, and summaries. In the following example, a quotation and a paraphrase are used to support a point introduced in the first sentence of the paragraph:

In fact, pollution from power plants may worsen as the demand for electric power continues to increase. The U.S. Department of Energy (2012b) notes that “it is likely that the nation’s reliance on fossil fuels to power an expanding economy will actually increase over at least the next two decades even with aggressive development and deployment of new renewable and nuclear technologies” (para. 1). Moreover, demand in developing nations is expected to increase even more dramatically. Of the nearly 1,200 conventional, coal-fired power plants now on the drawing board world wide, most are in developing countries (Plumer, 2012). The addition of so many new plants will almost certainly lead to more global air pollution in the near term.

Quoting an authority on the issue, the U.S. Department of Energy, lends strength to the argument. The quotation, along with a subsequent paraphrase of a passage from another source, serves as evidence to support the point. The writer follows the quotation and paraphrase with a sentence that restates the point. (See Chapter 19 for more about integrating information from sources.)