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. Cohesion is about the “sense of flow” (how each sentence fits with the next), while coherence is about the “sense of the whole.” Some students worry too much about “flow” and spend a lot of time on sentence-level issues to promote it. We encourage you to focus on the underlying structure. For the most part, a text reads smoothly when it conveys a thoughtful and 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 wordsmithing later, refining the analysis as you go. Therefore, we will discuss creating cohesion and coherent paragraphs 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. Deal with cohesion and coherence during the editing–not the drafting–process.

Cohesion refers to the flow from sentence to sentence. For example, compare these passages about how cliques form:

Version A has the exact same information as version B, but it is harder to read because it is less cohesive. In version B, however, each sentence begins with old information and bridges to new information. Here’s Version B again with the relevant parts emboldened:

The first sentence 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 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.

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:

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. 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; one just has to continue thinking it through in order to identify a clear argumentative purpose for each paragraph. With its purpose defined, each paragraph then becomes a lot easier to write. Coherent paragraphs aren’t just about style; they are a sign of a thoughtful, well-developed analysis.

Conclusion Sentences

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 quote), but as long as the paragraph succeeds in carrying out the task that it has been assigned by its key 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 :

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:

The last sentence of the paragraph doesn’t mirror the first, but the paragraph still works just fine. In fact, it serves as a transition into what is likely the focus of the next paragraph. In general, every sentence of academic writing should add some unique content. Don’t trouble yourself with having the last sentence in every paragraph serve as a mini-conclusion. Instead, worry about developing each point sufficiently and making your logical sequence clear.

Creating Coherence with Transitions

To ensure continuity within a paragraph, a writer must use key terms and other techniques, such as transitions. Transitions ensure that the reader understands what each sentence says and indicate how the sentences and paragraphs are logically related to each other and the “story.” Transitions should be placed at the beginning of a sentence for the strongest continuity, usually set off by a comma.

If transitions are missing, the logical relationship between sentences can be unclear and may even be nonexistent. Don’t assume your reader knows the relationship between the sentence. The importance of adding transitions is shown in the following example:

The logical relationship between the first and second sentences of this example is not immediately obvious to the reader. Possible transitions that one could fill in between these two sentences include the following:

When the transition is missing between these two sentences, most readers may guess that the intended relationship is “in addition” when it really is “therefore.” But readers should not have to guess. Sometimes readers can come to a very different conclusion than you intend!

Here is another example:

In the above example, the logical relationship between the first and second sentences is also not clear because a transition is missing. Once the transition is added in, the relationship between the two sentences becomes obvious.

Revised example:

Use transitions to link ideas, but do not overuse them. Certain transitions are outdated or are used in British, but not American, English, such as: hitherto, whilst, and henceforth.

Transitions to Use with Supporting & Concluding Sentences

A strong paragraph moves seamlessly from the topic sentence into the supporting sentences and on to the concluding sentence. To help organize a paragraph and ensure that ideas logically connect to one another, writers use transitional words and phrases. A transition is a connecting word that describes a relationship between ideas. Take another look at the earlier example:

Each of the underlined words is a transition word. Words such as first and second are transition words that show sequence or clarify order. They help organize the writer’s ideas by showing that they have another point to make in support of the topic sentence. Other transition words that show order include third, also, and furthermore.

The transition word because is a transition word of consequence that continues a line of thought. It indicates that the writer will provide an explanation of a result. In this sentence, the writer explains why hybrid cars will reduce dependency on fossil fuels (because they do not require gas). Other transition words of consequence include as a result, so that, since, or for this reason.

The following chart provides some useful transition words to connect supporting sentences and concluding sentences.