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How to Use Sources in an Expository Essay


Let's take a quick look at a sample essay that uses sources. Our goal is to examine the techniques used by the student author, Jane Doe, to integrate research into her expository essay done in APA style.

APA Level 1 Subheadings
First, note that in APA style, all major sections have a subtitle on top of them. In this five-paragraph essay, the main sections are single paragraphs, so that is where you will see the titles and subtitles. The first paragraph is the introduction paragraph, and you see the repetition of the main title from the title page on top of the intro paragraph—this is standard APA style.

Say Hello to the Intro
Next comes the introduction paragraph itself, which serves several functions.
  • provides background context for the topic
  • generates reader interest
  • introduces the thesis, which should come at or near the end of the paragraph
Let read Jane’s thesis and examine how she led up to it.

Thesis: “The result is that prison overcrowding is a serious financial burden for Americans.”

So, this is the overall concept, the controlling idea that the essay will illustrate, corroborate and, hopefully, present a convincing case for. Let’s return to the beginning of the intro to see how she led up to this thesis. Her introduction begins: “Something needs to be done about prison overcrowding and the lack of rehabilitation programs.”  This is Jane’s thought and opinion expressed in her own words.

Example of General Knowledge
Next sentence—“Without proper rehabilitation, prisoners become repeat offenders.” These are also Jane’s words. However, does this idea (the lack of rehabilitation causes repeat offenders) need a citation?

No, it does not. Anyone who has studied this issue, and Jane has, knows the terrible problem of repeat offenders because of the lack of rehabilitation in these human warehouses we’ve created.  Jane’s statement is probably an example of General Knowledge, which is something Jane (and most adults in America) probably knew before even beginning the paper. The high rate of repeat offenders is a generally accepted and unfortunate fact.

Example of Common Knowledge
Next sentence: “This means we have to build new facilities just to keep up with the overcrowding.” Again, these are Jane’s words. But this idea is pretty specific and probably not something Jane knew before she began researching the topic. So, does the sentence need a citation?

No. And here’s why: Common Knowledge. Common knowledge is something known by everyone or nearly everyone in a specific field or academic discipline. It usually does not have to be cited because it’s not associated with a single author anymore. In other words, before writing her paper, Jane probably didn’t know that “we have to build new facilities just to keep up with the overcrowding.” But once she began reading about America’s prison system, it became clear that this is common knowledge among researchers and writers in this field. They all share this idea and do not cite it. The knowledge is common to them.

Let’s look at this example from history: You’re writing a paper on the assassination of Abraham Lincoln, and you wish to use the following fact in your research essay:

Abraham Lincoln was shot by John Wilkes Booth. Would you have to cite that? No, it is an example of general knowledge—something known by most everyone without having to do any research.

Next: Abraham Lincoln was shot by John Wilkes Booth in Ford’s Theatre. Would you have to cite that? No. Although you may not have known the name of the theatre before you began your research, as you read about the assassination you saw that “Ford’s Theatre” is an example of common knowledge—something that is known by virtually every historian in the field.

Last: Abraham Lincoln was shot by the actor John Wilkes Booth in  Ford’s Theatre while watching the play “Our American Cousin.” Do any of those facts need citing? No. Booth’s profession (actor) and the name of the play are common knowledge. Perhaps you didn’t know that before you began researching, but as you read you saw these facts in virtually every source you consulted.

So, let’s return to Jane’s statement: “This means we have to build new facilities just to keep up with the overcrowding.” Is it general knowledge? No. Jane probably didn’t know it before she began researching. Is it common knowledge? Yes. As Jane did her research, she saw that this idea--the expanding need for new prison facilities--is a concept known and shared by experts in this field. Therefore, no citation is needed.

Back to Jane's Essay
Now this next sentence in her intro: “The current cost to our nation to incarcerate inmates is $75 billion per year, which is expected to quadruple in the next decade (Crawford, 2010).”

This is clearly statistical information associated with a single source, Crawford. It’s not common knowledge, and so must be cited. Notice that Jane chose NOT to quote from Crawford but to put the stats in her own sentence. This is a good choice because quotations should be used only when the original wording is important for some reason. It’s also easy to see a strong justification for the use of this source’s statistics: Jane’s subject is the financial burden of the prison system, so it was important for her to establish right away the numbers that support this notion of “financial burden.”

In her introduction, Jane used a single source in an effective way (summarized instead of quoted) for an important reason—to provide clarification of what she meant by “financial burden.” And this in-text citation (Crawford, 2010) refers to the full reference citation on the References page at the end of the paper.

Beefing Up the Body
Let’s turn now to Jane’s first body paragraph with the APA Level One subheading, Rehabilitation. Note that in this paragraph, Jane uses the classic formula for a body paragraph in an expository essay. That formula is:
  1. State the main point of the paragraph
  2. Explain/elaborate on the main point
  3. Support the main point
  4. Conclude the paragraph, typically with your own words.
If you put a sentence in a body paragraph, if must fulfill one of those four functions or you should consider whether it belongs or not.

Let’s read the paragraph’s stated main point: “First, prison overcrowding is a financial burden because prisoners are not getting enough rehabilitation to transition back to society.” So, the point is stated in Jane’s own words (green) and becomes the point that the paragraph will have to develop and support to a convincing degree--“lack of rehabilitation.”

In the Explain/Elaborate sentence, Jane writes, “The responsibility of the Bureau of Prisons is to safely confine its prisoner population; however, another mission of the Bureau is to rehabilitate.” Since there is no citation, we assume that Jane found that the twin role of the Bureau of Prisons (confine and rehabilitate) is common knowledge among those who study this issue; in other words, it is stated repeatedly in the sources she consulted.

But then Jane does something smart. She chooses one of the experts who know about the dual role of the Bureau of Prisons to add the voice of authority to her paragraph: She summarizes the opinion of an expert named Pavis in her first support sentence. Jane writes in her own words: “We must provide inmates with skills that will aid them in their ability to readjust after being released” (Pavis, 2012). When we check on the reference page citation, we see that Pavis was writing for an academic journal.

What you see at this point in Jane’s paragraph is another common use of research—to support a point you have just stated in your own words. Doing so shows that what you assert is accepted by experts in this field, and therefore your assertion is given credibility.

Now let’s look at Jane’s next two sentences: “Most inmates come to jail with little or no education at all. Once released, these prisoners are right back where they started from.”

Again, due to her research and thinking on this topic, Jane has formed some specific opinions. These opinions belong to her and are expressed in her own words. But because this is an academic research essay, Jane also knows that she must add the voices of published authorities to support her assertions.

In this case, she chooses an article that Talbot published in 2008. Let’s read this quotation and see if there is justification for using the author’s exact words to take up space in Jane’s paper.

"Talbot (2008) states, 'Many will be drug abusers who received no treatment for their addiction while on the inside, sex offenders who got no counseling, and illiterate high school dropouts who took no classes and acquired no job skills.'"

That was well written by Talbot and paints a bleak picture of people who are doomed to repeat offensives due to the lack of basic help. One other thing to notice is how Jane set up the Talbot quote with her lead-in sentence: “Once released these prisoners are right back where they started from.” And then she lets Talbot tell us exactly who these prisoners are why their relapse is likely.

The lack of rehabilitation—the subject of this paragraph—is driven home with Jane’s concluding sentence, which should be in her own words unless there is some compelling reason for it not to be: “The more prisoners that are rehabilitated, the quicker they can start to contribute to society once they are released.” After the dark picture she has painted, she provides the solution—the same one she opened with at the top of the paragraph—the need for more rehabilitation.

Quik Review
1. Common Knowledge—these are facts and concepts already known by those who regularly write and research in a given area. You will be acquiring common knowledge as you research. As long as you are sure you have seen this information in the majority of sources you consulted, you do not need to cite it.

2. Your Own Opinions—as a product of your reading and thinking about the topic, you will synthesize the material to form your own opinions, your own positions and beliefs. These are also yours and don’t need to be cited. However, it is a very, very good idea to add the voice of published experts to back up your opinions, especially in the form of quotations and paraphrases.

3. Summarize or Quote? You can do only two things with a source: summarize information from it in your own phrasing and sentences, or quote from it directly. Before choosing which option to use, be sure to have a good reason to do one or the other.

4. Signal Phrase. Finally, it’s always a good idea to introduce any quote you use with a signal phrase. Quotes shouldn’t seem like they just dropped out of the sky and landed in your paper. You should introduce who is speaking and it should be clear how the quote relates to the sentence immediately before it.

Follow those four strategies and you’ll be well on your way to using research effectively in your essays.

Good luck!