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)
|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.
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.
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.
Paragraph focus and coherence
Effective paragraphs focus on an idea and develop it. As you edit your draft, make sure that the sentences in your paragraph relate directly, not only to the general topic of the essay, but also to the specific idea or argument expressed in the topic sentence. Just because a sentence relates broadly to the topic in question does not necessarily make it relevant to the point you are arguing.
Take the following example.
Over the years, capital punishment has not significantly reduced violent crime. Statistics show that the number of murders in jurisdictions without capital punishment is no higher than in those jurisdictions that impose capital punishment for murder convictions. Interviews with those convicted of premeditated murder on death row have also revealed that the idea that they might die for their actions never entered their minds prior to or during the murder. Moreover, these same statistics reveal it is more than twice as likely that convicted murderers who are people of colour will receive the death penalty than their white counterparts. This is clearly an injustice that must be righted.
The above paragraph is successful until the end of the third sentence. The second and third sentences work to develop the main idea of the first sentence. The fourth and fifth sentences, however, are out of place in this paragraph. The fourth sentence still deals with capital punishment and violent crime, so it is not completely off-topic. However, the main idea introduced in this sentence—that convicted people of colour are more likely to be executed than whites—is largely irrelevant to the particular argument introduced in the first sentence (i.e., the relationship between capital punishment and the deterrence of violent crimes). The fifth sentence builds upon the previous sentence, but switches the focus again toward the idea of injustice, which, although important, does not help prove the point that capital punishment does not deter violent crime. Although the content of the fourth and fifth sentences is generally related to issues of capital punishment, it does not relate to the particular focus of the paragraph.