How to Write a Compare and Contrast Essay

What is a compare and contrast essay?

A compare and contrast essay puts two or more subjects — texts, thinkers, events, theories, policies — side by side and explains what the pairing reveals. Comparing means identifying similarities; contrasting means identifying differences. Most assignments want both, even when the prompt uses only one word.

The common failure is the essay that lists: “Both novels were published in the nineteenth century. Both follow a young woman. One is set partly in a school.” Each sentence is accurate, and together they prove nothing. A strong comparison has a purpose. It might show that two subjects that look alike differ in one decisive way, that two that look different share a hidden assumption, or that one subject explains something puzzling in the other. That purpose becomes your thesis, and it is what a marker is really grading.

Choose a basis of comparison

A basis of comparison, sometimes called a frame of reference, is the specific question you put to both subjects. “Compare Pride and Prejudice and Jane Eyre” is too open; you could compare their settings, their prose styles, their publication histories. “Compare how Elizabeth Bennet and Jane Eyre weigh marriage against independence” gives you a basis, and every paragraph can serve it.

If your instructor sets the subjects, you still choose the basis. If you choose the subjects too, pick a pair with enough in common to make differences meaningful: two thinkers answering the same question, two cities facing the same problem, two translations of the same poem. A good basis passes these tests:

• It applies to both subjects in roughly equal depth.
• It is narrow enough to cover in your word count, usually three to five criteria.
• It leads somewhere: answering it tells the reader something about both subjects, or about the wider topic.
• You have evidence for both sides of it, not just for the subject you know better.

Map similarities and differences in a grid

A Venn diagram is a fine start, but a comparison grid is more useful for planning. Put your criteria in rows and your subjects in columns, and fill each cell with a short note and a page reference. The grid below compares Thomas Hobbes's Leviathan (1651) and John Locke's Second Treatise of Government (1689) on the state of nature and government, a classic pairing in political philosophy; the guide to starting the great books suggests reading the two side by side.

Once the grid is filled, read across each row and ask what the difference means. In the Hobbes and Locke grid below, the rows on rights and resistance turn out to depend on the first row: once Locke places rights in the state of nature, a limited government follows. That dependency is the beginning of a thesis.

Write a thesis that says what the comparison shows

A compare and contrast thesis names the subjects, the basis and the insight. Weak: “Hobbes and Locke have both similarities and differences in their views of government.” That is true of any two philosophers. Stronger: “Hobbes and Locke both ground government in consent, but because Locke's state of nature already contains rights, his government is limited by them, while Hobbes's sovereign is limited by almost nothing.”

The stronger version tells the reader where the essay is going: it will show the shared starting point, then trace one decisive difference to its consequences. Three thesis shapes work especially well — alike on the surface but different in one decisive way, different on the surface but sharing a hidden assumption, or one subject used as a lens to explain the other. For more on building the sentence, see the guide to writing a thesis statement.

Block or point-by-point: compare and contrast essay structure

There are two standard ways to organize the body, plus a hybrid. In block structure you discuss everything about subject A, then everything about subject B, and draw the comparison in the second block and the conclusion. In point-by-point structure each paragraph takes one criterion and discusses both subjects. A hybrid gives each subject a short block for context, then compares point by point. Whichever you choose, sketch it first; the guide to outlining an essay shows how.

How to write a compare and contrast essay in seven steps

From prompt to final draft, this order keeps the comparison purposeful:

1. 1Identify exactly what the prompt asks you to compare, and whether it wants similarities, differences or both.
2. 2Choose a basis of comparison and three to five criteria that serve it.
3. 3Build a grid with criteria as rows, subjects as columns, and a note and page reference in every cell.
4. 4Read across the rows, find the most revealing difference or similarity, and write a thesis about it.
5. 5Choose block, point-by-point or hybrid structure, and outline the paragraphs.
6. 6Draft, giving each subject comparable space and making every paragraph end on what the comparison shows.
7. 7Revise for balance: if one subject gets twice the words of the other, rebalance or justify the imbalance.

Language for comparing and contrasting

Transitions are where a comparison becomes visible. Choose words that state the exact relationship, not just that you are moving on. “On the other hand” is overused and often wrong, since it implies opposition. Use these by function:

• Similarity: likewise, similarly, in the same way, both … and, neither … nor.
• Difference: whereas, while, by contrast, unlike, in contrast to.
• Qualified similarity: although both, while each, despite sharing.
• Consequence of a difference: as a result, this is why, which explains.

Common compare and contrast essay mistakes

The most frequent mistake is the list without a point: paragraph after paragraph of accurate observations that never add up to a claim. Close behind is imbalance, where one subject gets detailed analysis and the other a few sentences, usually because the writer knows one subject better. Check your draft by highlighting each subject in a different color; the page should be roughly balanced.

Other problems are easier to spot. Too many criteria make every comparison shallow, so cut to the three or four that matter most. Comparing things with no real common ground produces an essay with nothing to say. And forgetting the conclusion's job — saying what the comparison as a whole revealed — leaves the reader with parts but no whole.