As Michael Harvey writes, paragraphs are, in essence, “a form of punctuation, and like other forms of punctuation they are meant to make written material easy to read.”^[1] Effective paragraphs are the fundamental units of academic writing; consequently, the thoughtful, multifaceted arguments that your professors expect depend on them. Without good paragraphs, you cannot clearly convey sequential points and their relationships to one another. Each paragraph provides space for a body of evidence that proves a particular aspect of your claim: the paragraph units need to seem focused within themselves, and linked between each other in a specific order that moves readers forward through your paper.

Many novice writers tend to make a sharp distinction between content and style, thinking that a paper can be strong in one and weak in the other, but focusing on paragraphs as organizational units shows how content and style converge in deliberative academic writing. Your professors will view even the most elegant prose as rambling and tedious if there isn’t a carefully constructed, cohesive argument unfolding logically across the topic sentences, backed up by the right evidence in the right place at the right time.

Topic Sentences

In academic writing, readers expect each paragraph to open with a sentence or two that captures its main point. They’re often called “topic sentences,” although the phrase “topic sentence” can make it seem like the paramount job of that sentence is simply to announce the topic of the paragraph, and that it must always be a single grammatical sentence. A topic sentence expresses the central idea of the paragraph in terms of the central thesis of your essay. And sometimes a question or a two-sentence construction functions as the key to those central concepts.

Topic sentences in academic writing do two closely related things. First, they establish the main point that the rest of the paragraph supports. Second, they situate each paragraph within the sequence of the argument, a task that requires both transitioning from the prior paragraph and restating what this particular paragraph adds to the central thesis. Don’t be afraid of repetition. If your topic sentences aren’t repeating a key term or concept from your introduction, readers will feel disoriented because you appear to be asking them to think about something new rather than developing an idea they knew to expect. You are not trying to catch an academic reader unawares! If you do, the reader will get jumpy (“What will the next paragraph ask me to think about?? Bananas? Aircraft carriers? Montenegro?”). Feel free to impress your readers with the elegance, soundness, and complexity of your thinking, but don’t subject them to topic sentence jump scares.

Consider these two examples:^[2]

• Version A:
• Now we turn to the epidemiological evidence.
• Version B:
• The epidemiological evidence provides compelling support for the hypothesis emerging from these etiological studies.

Both versions convey a topic; it’s pretty easy to predict that the paragraph will be about epidemiological evidence, but only the second version establishes an argumentative point and puts it in context. This topic sentence doesn’t just announce the existence of the epidemiological evidence; it shows how epidemiology is telling the same story as etiology. That story, or hypothesis, must be the thesis of this paper (and giving that concrete sense of the stakes is probably the job of the following sentence, because not all ideas fit elegantly into one sentence, and there’s no rule that says a topic sentence must be literally only one sentence). Seeing these two ideas connected will come as a relief to your reader, who wants reassurance that all this thinking about epidemiology and etiology will serve a coherent claim. Put another way, while Version A doesn’t relate to anything in particular, Version B immediately suggests that the prior paragraph addresses the biological pathway (i.e., etiology) of a disease and that the new paragraph will bolster the emerging hypothesis with a different kind of evidence. As a reader, it’s easier now to keep track of how the paragraph about cells and chemicals and such relates to the previous paragraph about populations in different places. Presumably, these two paragraphs occur in this order, and not the reverse order, because readers will move more easily in this argument from etiology to epidemiology than the other way around: topic sentences move the reader through the arc of your thesis in the most logical way possible, which often means that the more familiar or more foundational material structures the earlier paragraphs. Topic sentences shouldn’t give the impression that your paragraphs follow an order no more compelling than “Another thing I want to talk about is…”

A point to emphasize about key sentences is that academic readers expect them to be at the beginning of the paragraph, and not at the end. You don’t build up to a topic sentence; you use it to set the scene, and then build up evidence to support it. This placement at the start helps readers comprehend your argument and easily follow the sequence of logic. 

Knowing this convention of academic writing can help you both write and read more effectively. When you’re reading a complicated academic piece for the first time, you might want to go through reading only the first sentence or two of each paragraph to get the overall outline of the argument. Then you can go back and read all of it with a clearer picture of how each of the details fit in. And when you’re writing, you may also find it useful to write the first sentence of each paragraph (instead of a topic-based outline) to map out a thorough argument before getting immersed in sentence-level wordsmithing.

Cohesion and Coherence

With a key sentence established, the next task is to shape the body of your paragraph to be both cohesive and coherent. As Joseph Williams and Joseph Bizup explain, cohesion is about the “sense of flow” (how each sentence fits with the next), while coherence is about the “sense of the whole” (how all the sentences in a paragraph focus on the same topic).^[3]  

For the most part, a text reads smoothly when it conveys a well organized argument or analysis. Focus first and most on your ideas, on crafting an ambitious analysis. The most useful guides advise you to first focus on getting your ideas on paper and then revising for organization and word choice later, refining the analysis as you go. Thus, consider the advice here as if you already have some rough text written and are in the process of smoothing out your prose to clarify your argument for both your reader and yourself.

Cohesion

Cohesion refers to the flow from sentence to sentence. For example, compare these passages:

Version A:

Granovetter begins by looking at balance theory. If an actor, A, is strongly tied to both B and C, it is extremely likely that B and C are, sooner or later, going to be tied to each other, according to balance theory (1973:1363). Bridge ties between cliques are always weak ties, Granovetter argues (1973:1364). Weak ties may not necessarily be bridges, but Granovetter argues that bridges will be weak. If two actors share a strong tie, they will draw in their other strong relations and will eventually form a clique. Only weak ties that do not have the strength to draw together all the “friends of friends” can connect people in different cliques.^[4] 

Version B:

Granovetter begins by looking at balance theory. In brief, balance theory tells us that if an actor, A, is strongly tied to both B and C, it is extremely likely that B and C are, sooner or later, going to be tied to each other (1973:1363). Granovetter argues that because of this, bridge ties between cliques are always weak ties (1973:1364). Weak ties may not necessarily be bridges, but Granovetter argues that bridges will be weak. This is because if two actors share a strong tie, they will draw in their other strong relations and will eventually form a clique. The only way, therefore, that people in different cliques can be connected is through weak ties that do not have the strength to draw together all the “friends of friends.”^[5]

Version A has the exact same information as version B, but it is harder to read because it is less cohesive. The paragraph in version B feels more cohesive because each sentence begins with old information and bridges to new information. Note that “old” is a relative term: it might be something you’ve known for years, or it might only be as old as one sentence ago. You can convey a lot of new information to your readers if you keep presenting and linking what’s new to what’s familiar, even if none of the material was “old news” to you five minutes earlier. 

The first sentence in this example establishes the key idea of balance theory. The next sentence begins with balance theory and ends with social ties, which is the focus of the third sentence. The concept of weak ties connects the third and fourth sentences and the concept of cliques connects the fifth and sixth sentences. In Version A, in contrast, the first sentence focuses on balance theory, but then the second sentence makes a new point about social ties before telling the reader that the point comes from balance theory. The reader has to take in a lot of unfamiliar information before learning how it fits in with familiar concepts. Version A is coherent, but the lack of cohesion makes it tedious to read.

Coherence

While cohesion is about the sense of flow, coherence is about the sense of the whole. For example, here’s a passage that is cohesive (from sentence to sentence) but lacks coherence:

Your social networks and your location within them shape the kinds and amount of information that you have access to. Information is distinct from data, in that it makes some kind of generalization about a person, thing, or population. Defensible generalizations about society can be either probabilities (i.e., statistics) or patterns (often from qualitative analysis). Such probabilities and patterns can be temporal, spatial, or simultaneous.

Each sentence in the above passage starts with a familiar idea and progresses to a new one, but it lacks coherence—a sense of being about one thing. In fact, it feels like an introduction to several main concepts of Communication crammed into one paragraph: this essay, if it were submitted in this form, would quickly overwhelm and exhaust its reader.

Note, though, that good writers often write passages like that when they’re free-writing or using the drafting stage to cast a wide net for ideas. A writer weighing the power and limits of social network analysis may free-write something like that example and, from there, develop a more specific plan for summarizing key insights about social networks and then discussing them with reference to the core tenets of social science. As a draft, an incoherent paragraph often points to a productive line of reasoning—you just have to continue thinking it through in order to identify a clear argumentative purpose for each paragraph. With its purpose defined, each paragraph becomes a lot easier to write. Coherent paragraphs aren’t just about style; they are a sign of a focused, well developed analysis.

Concluding a Paragraph

Some guides advise you to end each paragraph with a specific concluding sentence—in a sense, to treat each paragraph as a kind of mini-essay—but that’s not a widely held convention. Most well written academic pieces don’t adhere to that structure. The last sentence of the paragraph should certainly be in your own words (as in, not a quotation or paraphrase of somebody else’s ideas about your topic), but as long as the paragraph succeeds in carrying out the task that it has been assigned by its topic sentence, you don’t need to worry about whether that last sentence has an air of conclusiveness. For example, consider these paragraphs about the cold fusion controversy of the 1980s that appeared in a best-selling textbook:^[6]

The experiment seemed straightforward, and there were plenty of scientists willing to try it. Many did. It was wonderful to have a simple laboratory experiment on fusion to try after the decades of embarrassing attempts to control hot fusion. This effort required multi-billion dollar machines whose every success seemed to be capped with an unanticipated failure. ‘Cold fusion’ seemed to provide, as Martin Fleischmann said during the course of that famous Utah press conference, ‘another route’—the route of little science.

In that example, the first and last sentences in the paragraph are somewhat symmetrical: the authors introduce the idea of accessible science, contrast it with big science, and bring it back to the phrase “little science.” Here’s an example from the same chapter of the same book that does not have any particular symmetry:^[7]

The struggle between proponents and critics in a scientific controversy is always a struggle for credibility. When scientists make claims which are literally ‘incredible,’ as in the cold fusion case, they face an uphill struggle. The problem Pons and Fleischmann had to overcome was that they had credibility as electrochemists but not as nuclear physicists. And it was nuclear physics where their work was likely to have its main impact.

The last sentence of the paragraph doesn’t mirror the first, but the paragraph is in great shape, coherently connecting its initial, general claim about credibility to the specific challenge to the credibility of Pons and Fleischmann. In general, don’t trouble yourself with having the last sentence in every paragraph serve as a mini-conclusion if it feels forced. Instead, worry about developing each point sufficiently and making your logical sequence clear. Let your topic sentences do most of the work of keeping your essay coherent and giving it forward momentum.

Conclusion: Paragraphs as Punctuation

To reiterate the initial point, it is useful to think of paragraphs as punctuation that organize your ideas in a readable way. Each paragraph should be an irreplaceable node within a coherent sequence of logic. In a successful, coherent college paper, the structure of each paragraph reflects its indispensable role within the overall piece. Make every bit count and have each part situated within the whole.