How to Write a Compare and Contrast Essay

The comparison essay I still think about was four pages on cats versus dogs. Cats are independent; dogs are loyal. Cats use a litter box; dogs need walking. Cats purr; dogs bark. By the last paragraph I knew a good deal about both animals and had no idea why the student had put them in the same room. There was no question the essay was trying to answer. There was only a pile.

I have graded a few thousand of these since, and the cats-and-dogs problem shows up in most of the weak ones, dressed in more academic clothing. Two novels, two economic policies, two painters, two programming languages: the writer inventories likenesses and differences, tidies them into paragraphs, and stops. What follows is how I teach students to get past the pile, from picking the pair to writing the transitions.

The pair has to share a question, not just a category

Any two things can be compared. That is the trouble. The fact that both subjects exist, or both belong to some broad class like “novels” or “cities,” is not a reason to write about them together. What you need is a basis for comparison: a specific question that both subjects answer, and answer differently enough (or similarly enough, against expectation) that putting them side by side teaches the reader something.

Here is the test I ask students to run before they write a word. Finish this sentence: “Looking at A and B together shows us ___ about ___.” If the first blank is “their similarities and differences,” you do not have a basis yet. If the second blank is empty, same problem. A workable answer sounds like this: “Looking at these two adaptations together shows us how much the meaning of the original scene depends on who gets the last line.” That is a question about adaptation, and both films answer it.

Notice that the strongest pairs are usually close rather than distant. Two war poems written a decade apart by writers who read each other give you far more to say than a war poem and a haiku about a frog. Closeness is what makes the differences meaningful. When the subjects are far apart, the differences were obvious before you started. A quick check: list what the two share in one column and what separates them in another. If either column is nearly empty, reconsider the pair.

Your thesis is a verdict on the comparison

Once you know the question, the thesis is your answer to it. This is where most comparison essays lose their argument before the first body paragraph, because the writer settles for a thesis that only announces the topic: “While both authors write about grief, they approach it in different ways.” True. Also true of every two authors who have ever written about grief. Nothing is at stake.

A thesis for this essay type has to say what the comparison reveals. Some patterns that work:

• One subject does the job better for a stated purpose. (“For a first-year student learning to code, language A’s error messages teach more than language B’s speed saves.”)
• An apparent contrast hides a shared assumption. (“The two policies look like opposites, but both assume the market will absorb the cost, and that assumption is where each fails.”)
• An apparent similarity breaks down under pressure. (“Both memoirs open with the same scene, but one uses it to excuse the narrator and the other to indict her.”)
• The pairing exposes something about the category itself. (“Reading these two dystopias together shows how quickly the genre stopped fearing the state and started fearing the neighbor.”)

Every one of those gives the essay somewhere to go. The body paragraphs stop being a tour and become evidence for a claim. If your thesis could be pasted onto any other pair of subjects with a word swapped, it is not doing its job. The general craft of writing a claim that can be argued with is covered in my guide on how to write a thesis statement, and everything there applies here, with one addition: the thesis should name both subjects and hint at the basis for comparison, so the reader knows the rules of the game from the first paragraph.

Block or point by point: picking the skeleton

There are two standard ways to organize the body, and neither is better in the abstract. They fit different essays.

	Block method	Point-by-point method
Structure	All of subject A, then all of subject B, same points in the same order	One criterion per paragraph, both subjects examined under it
Best for	Short essays, two or three points, subjects the reader may not know	Longer essays, four or more points, analytical arguments
Strength	Easy to draft; each subject gets an uninterrupted portrait	Subjects stay in contact; the comparison happens on every page
Weakness	Can split into two summaries with a thin ending	Needs careful transitions; can feel choppy if paragraphs are short
Where the argument lives	Mostly in the second half and the conclusion	In every paragraph

Students reach for the block method first because it is easier to draft. You describe one thing, then the other. The danger is that the reader finishes the section on subject A having forgotten what the essay was about, and the section on subject B reads as a second, unrelated report. If you use block structure, fight that. Refer back to A while writing about B (“Where the first film cuts away here, the second holds the shot”), and give the conclusion enough room to do the actual comparing.

Point-by-point is more work and almost always the stronger choice for an argumentative essay. Each paragraph picks one criterion, examines both subjects under it, and states what the difference or likeness means for the thesis. The cost is that you switch subjects constantly, so your transitions have to be clean or the paragraphs feel like a tennis match.

My rule of thumb: under 800 words with three points or fewer, block is fine. Anything longer or more analytical, go point by point. If you are unsure, draft point by point, because it forces you to have something to say about each criterion for both subjects. Gaps show up immediately.

Choosing points of comparison that carry weight

A point of comparison is a criterion: a lens you hold both subjects up to. Price, tone, audience, historical moment, treatment of a particular theme, what happens in the final scene. The mistake is to choose points because they are easy to fill rather than because they matter to the argument.

Three questions sort the strong points from the filler:

1. Does this point bear on my thesis? If the thesis is about how two novels handle guilt, a paragraph on their publication history is decoration unless it explains something about the guilt.
2. Do the subjects actually differ (or surprisingly agree) on this point? A criterion where both subjects behave identically is dead weight, unless the identity is the argument.
3. Can I show it, not just state it? If you cannot quote, cite, or describe a specific moment for each subject under this criterion, you are asserting rather than comparing.

Three points that pass all three questions beat six that pass one. Order them by force: the strongest goes last, where it will be remembered, and the weakest in the middle. Resist the urge to balance similarities and differences for their own sake. If your argument rests on contrast, two paragraphs of dutiful similarities before you get there will bore the reader and undercut the claim.

A worked example: two ways of taking notes

Let me build one from scratch so the moves are visible. Suppose a student picks handwritten notes versus typed notes in lectures. Familiar enough to be relatable, narrow enough to argue.

The basis for comparison: both are methods of capturing a lecture, and the question is which one serves a student who needs to understand the material rather than transcribe it. Both methods answer that question.

The thesis. A weak version: “Handwriting and typing each have advantages and disadvantages.” A working version: “Typing captures more of a lecture, but for a student who needs to understand rather than record it, handwriting wins, because the very slowness that makes it capture less forces the note-taker to decide what matters in the moment.”

That thesis concedes the obvious point in favor of typing, names the criterion that decides the question (understanding, not volume), and gives the mechanism (slowness forces selection). The body now has a job.

The points. The student brainstorms seven: speed, volume captured, distraction, retention, searchability, cost, and what happens during review. Cost drops out (both are cheap, and it has nothing to do with understanding). Searchability is real but irrelevant to the thesis. Speed and volume collapse into one point, because they are the same fact. That leaves three: speed and selection, distraction, and review.

The structure. Three points, roughly 1,200 words, an argumentative thesis: point by point. The paragraphs would run like this:

• Speed and selection. Typing keeps pace with speech, so the typist transcribes. Handwriting cannot, so the hand-writer compresses and chooses. The concession (typing captures more) becomes the setup for the argument (choosing is the understanding).
• Distraction. A laptop is a window onto everything else; a notebook is a notebook. Both subjects under the criterion, with a concrete moment for each: the tab that opens during a slow stretch versus the doodle in the margin that at least stays on the page.
• Review. Typed notes are complete and, precisely because of that, rarely reread. Handwritten notes are gappy, and filling the gaps during review is a second pass at the material. This is the strongest point, so it goes last.

The conclusion does not repeat the three points. It answers the question the essay asked at the start: for understanding, the slower tool is the better one, and the student who wants both can type the lecture and then rewrite it by hand. The comparison has produced a recommendation neither method suggested on its own, and that is the whole reason to write one.

Transitions that keep both subjects in the frame

In a point-by-point essay you change subjects every few sentences. In a block essay you change subjects once, but the reader has to carry the first subject across several paragraphs. Either way, the transitions are where the comparison actually happens on the page, and weak ones are what make the essay feel like a list.

Signal words help (“similarly,” “by contrast,” “whereas,” “in the same way,” “unlike”), but they are not the transitions themselves. They are labels. The real transition is a sentence that names the relationship between what you just said about A and what you are about to say about B. Compare:

• “Similarly, the second novel also uses a child narrator.”
• “The second novel hands the story to a child for the same reason the first did: a narrator who cannot yet judge lets the reader do the judging.”

The first sentence says a similarity exists. The second says what it is for. Every transition in a comparison essay should be doing that second kind of work. If you find yourself writing “another difference is,” stop, ask what the difference means, and write that instead.

One small habit that helps: in point-by-point essays, open each paragraph with the criterion, not with a subject (“On the question of what the ending forgives” rather than “In the first film”). The reader then knows what the paragraph is measuring before either subject appears.

Climbing out of the list trap

You will know you have fallen in when a paragraph could be reordered without loss, or when a reader could delete the conclusion and miss nothing. The essay has become an inventory. It happens to careful students more than careless ones, because careful students find a lot of material and hate to waste it.

The way out is subtraction and pressure. Cut every point of comparison that does not push the thesis. Then, for each surviving point, add one sentence that starts with “which means” and finishes the thought. If you cannot finish it, the point is decoration, and it goes too. Three points that each earn a “which means” will outscore eight that do not, on every rubric I have ever used.

The other symptom is a conclusion that says the two subjects “both have strengths and weaknesses.” That sentence is what writers produce when they have not decided. Decide. You can qualify a verdict, limit it to a purpose, or admit a case where it flips, but you have to give one. The reader put two things side by side on your instruction and deserves to be told what they saw.

What I look for on the page

When I grade these, I read the thesis first and ask whether it makes a claim I could disagree with. Then I skim the topic sentences and check that each one names a criterion or a relationship, not just a subject. Then I read the conclusion and ask whether it says something the introduction did not. An essay that passes those three checks is usually strong before I have read a body paragraph in full.

Before you submit, run the same checks yourself. Can the thesis be argued with? Does each paragraph compare, rather than describe? Does the conclusion deliver a verdict the comparison earned? If the answer to all three is yes, you have written an argument, not a pile, and the cats and dogs can rest.