When To Cite Sources

Any time you quote more than a few words from a source, cite the source (including page numbers, if any) and put the words in quotation marks or a block quote.<

Here's an excerpt from a original source, a 2008 statement by the World Health Organization about the importance of increasing worldwide breastfeeding rates:
Rapid improvements can be achieved if a breastfeeding culture once again permeates all levels of society. Mothers need support not only to begin breastfeeding within one hour of birth, but also to sustain exclusive breastfeeding for six months, and continue breastfeeding for two years or beyond, as well as giving other nutritious foods. They also need support to prevent and overcome breastfeeding difficulties and deal with competing demands on their time.<
Here's a properly cited quotation of that source:
In a 2008 statement on behalf of the World Health Organization, Director-General Margaret Chan called for “a breastfeeding culture [that] permeates all levels of society” (Chan 1). Chan believes that mothers need to be supported in their efforts to breastfeed, so that they can “initiate breastfeeding within one hour of birth . . . [and] sustain exclusive breastfeeding for at least six months" and partial breastfeeding for two years or more (1).<
The two passages quoted from Chan’s statement must not only be cited but also enclosed in quotation marks. Note how the writer used ellipses (. . .) to indicate omitted words and square brackets ([ ]) for words that were added. For more on quotations, see How to Quote and Paraphrase in the sidebar.

Any time you use distinctive words or phrases from a source, cite the source and put the words in quotation marks or a block quote.<

Here's an excerpt from a original source, a 2008 statement by the World Health Organization about the importance of increasing worldwide breastfeeding rates:
Rapid improvements can be achieved if a breastfeeding culture once again permeates all levels of society. Mothers need support not only to begin breastfeeding within one hour of birth, but also to sustain exclusive breastfeeding for six months, and continue breastfeeding for two years or beyond, as well as giving other nutritious foods. They also need support to prevent and overcome breastfeeding difficulties and deal with competing demands on their time.<
Here's a quotation of a phrase taken from that source:
In a 2008 statement on behalf of the World Health Organization, Director-General Margaret Chan called for a return to “a breastfeeding culture” for all families, rich and poor, in all countries. Chan believes that mothers need to initiate breastfeeding right after birth and then to continue exclusive breastfeeding for six months and partial breast-feeding for two years or more (1).<
Here, the passage from Chan is not quoted, but paraphrased. So the writer cites Chan as the source of the information, but does not add quotation marks, except for one phrase. Readers want to know when you have repeated a distinctive term or phrase that represents the specific thinking of your source: so in this example, the phrase breastfeeding culture is put in quotation marks because it points to a key idea that seems to be a distinctive feature of Chan’s statement. But readers don’t want to know every time you use a word or phrase that your source also happened to use: so in this example, the phrase exclusive breastfeeding is not in quotation marks because it is widely known to health officials, and so is not distinctive of Chan's paper.

Any time you paraphrase the words of a source, cite the source (do not use quotation marks).<

Here's an excerpt from the original source, a 2008 statement by the World Health Organization about the importance of increasing worldwide breastfeeding rates:
Rapid improvements can be achieved if a breastfeeding culture once again permeates all levels of society. Mothers need support not only to begin breastfeeding within one hour of birth, but also to sustain exclusive breastfeeding for six months, and continue breastfeeding for two years or beyond, as well as giving other nutritious foods. They also need support to prevent and overcome breastfeeding difficulties and deal with competing demands on their time.<
Here's a paraphrase of that source:
In a 2008 statement on behalf of the World Health Organization, Director-General Margaret Chan called for breastfeeding to be a normal practice for all families, rich and poor, in all countries. Chan believes that mothers need to start breastfeeding right after birth and then to continue exclusive breastfeeding for six months and partial breastfeeding for two years or more (Chan 1).<
Here, the passage from Chan is not quoted, but paraphrased. So the writer cites Chan as the source of the information, but does not add quotation marks. When you paraphrase, be careful not to follow your source too closely (see How to Quote and Paraphrase in the sidebar).

Any time you report quantitative data from a source, cite the source.<

Here's an example of a paper that cites a source's data:
Relatively few American children work and most who do hold jobs work not to support their families but to supplement their spending money. 21 percent of those in the lowest-income group held employee jobs when they were 14, compared with between 25 and 27 percent of those whose households had incomes in the three higher groups.1
  1. U.S. Department of Labor, "Report on the Youth Labor Force," June 2000, 14, http://www.bls.gov/opub/rylf/pdf/rylf2000.pdf.
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Readers want to know the source of any quantitative data that you report, including statistics, percentages, facts, graphs, or raw numbers. If you collected the data yourself, readers want to know how and where you collected it. If you found the data in a source, they want to know where you found it.

Any time you use ideas or methods you learned from a source, cite the source.<

Here's an example of a paper that cites a borrowed method:
Data collection centered on interviews, field notes, a researcher's log, and artifacts (postcards, comic-book images, written notes) collected from my participants. I analyzed their interview data using Kvale's meaning-interpretation method, where the researcher worked from a "theoretic stance, recontextualizing what [was] said in a specific conceptual context" (Kvale 1996, 201).<
Readers want to know what method you used to analyze your data. If the method is a standard, widely used one, you do not need to cite a source. But if the method is associated with a particular source, you must cite it. Notice also how the writer also quotes directly from the source in order to explain that method.