Paragraph Structure and Coherence

When you edit a paragraph, look at the functions of the sentences involved. What point are you trying to make, and how are you choosing to argue it? Why is the point significant in light of both previous ideas and the overall paper? Applying the what/how/why strategy to paragraph structure can help keep the paragraph focused and unified.

  • What (the point): The main idea you discuss in this paragraph (best introduced in a topic sentence, the introductory sentence to your paragraph); 1-2 sentences.
  • How (the proof): The evidence used to substantiate the point or back up the argument: examples, appropriate reference material, quotations, etc.; 2-4 sentences.
  • Why (the comment): Commentary outlining the significance of the preceding material. Your explanation of how and why these ideas fit together: relationships, contrasts, conclusions, etc.; 2-4 sentences.

a stock of multicoloured books

For example, if it takes more than one or two sentences to introduce the point of the paragraph, it is likely that you are trying to focus on too much within one paragraph, or that you are unclear on what the precise focus really is. Fewer than two sentences of supporting evidence or commentary usually signals a minor point; perhaps this idea is actually part of a larger notion rather than a discrete point requiring a paragraph of its own. Conversely, more than four sentences of commentary or supporting information might signal one of two things: you may be making the same point several times over (rather than building on a point with each sentence) or your evidence may be straying off into a new area, and thus requires a subsequent paragraph.Certainly, the above chart is intended as a guide, not rigid instructions. Not every paragraph functions in the manner described above; however, the what/how/why strategy can serve as a helpful logic barometer for your writing.

Paragraph focus

Effective paragraphs focus on one idea and develop it. As you edit your draft, make sure that the sentences in your paragraph relate directly, not only to the broader topic of the essay, but also to the specific idea or argument expressed in the topic sentence of the paragraph. Just because a sentence relates broadly to the topic in question does not necessarily make it relevant to the point you are arguing.

Here is an example of a paragraph drafted as part of a paper on municipalities and climate change.

Litigation is just one of several tools available to public officials to reduce CO2 emissions, and should not be viewed as a silver bullet; it takes time and money. However, the real value of climate change lawsuits may be that they can have a substantial influence on public opinion, thereby encouraging public pressure on oil companies to take responsibility for their role in climate change (Novel, 2019). Recent lawsuits launched by American municipalities such as New York and San Francisco have revealed to the public evidence that, for decades, oil companies have known of the risks of climate change and their own contribution to it (Hall, 2015; Keane, 2020; McGreal, 2021). These lawsuits claim that the companies are responsible for damage to public health, housing, and infrastructure through extreme weather events. Some of the well-documented effects of climate change on public health include exacerbating respiratory illnesses such as asthma, and preventing the public from exercising outdoors on extreme-heat days. Citizens who suffer the most from these effects tend to have low incomes and live in under-served areas of the municipalities, where they may be exposed to the worst effects of climate change.

The above paragraph works well until the end of the third sentence.

  • The first sentence is a transition sentence, linking to the previous paragraph’s topic (perhaps the previous paragraph described litigation in this context, or listed in more detail the “several tools” mentioned in this sentence).
  • The second sentence introduces the argument of the current paragraph (that climate change lawsuits are valuable, not because they are likely to hold oil companies responsible, but because they can influence the public’s opinion of oil companies, which in turn can pressure oil companies to change).
  • The third sentence develops this argument by offering an example and starting to show its relevance to the argument.

The fourth, fifth, and sixth sentences, however, are out of place in this paragraph.

  • The fourth sentence still deals with municipal lawsuits against oil companies, so it is not completely off-topic. However, the main idea introduced in this sentence—the claims of the lawsuits—is largely irrelevant to the particular argument introduced in the first sentence (i.e., the effects of these lawsuits, and the evidence they reveal, on public opinion of oil companies and climate change).
  • The fifth sentence switches the focus to the effects of climate change on human health, and the sixth sentence focuses on those who are most vulnerable to these effects. Although these topics are important, they do not help prove the point of the paragraph (that climate change lawsuits can influence public opinion) or link the point to the broader argument of the essay, perhaps by explaining how public opinion relates to reducing CO2 emissions.

Hall, S. (2015, October 26). Exxon knew about climate change almost 40 years ago. Scientific American.

Keane, P. (2020, September 20). How the oil industry made us doubt climate change. BBC News.

McGreal, C. (2021, June 30). Big oil and gas kept a dirty secret for decades. Now they may pay the price. The Guardian.

Novel, A. (2019, March). Climate change: A new subject for the law. UNESCO Courier.

Thomson Reuters. (2018, January 11). New York sues oil companies, plans divestment from pension funds. CBC News.