A compare and contrast essay sets two or more subjects side by side, on grounds they share, to make a point neither makes alone. Markers set it to see whether you can move from "these differ" to "and this is why it matters". A list of likenesses and differences is not yet the essay. EdCitation publishes this guide.
On 26 September 2026 we read the comparison guides of eight university writing centres in Canada and the United States, two published studies in full and one real university brief. Where the guides disagree, we say so. What every essay shares is covered elsewhere: essay structure, the thesis statement and paragraph patterns such as PEEL.
EdCitation never writes any part of an essay. Its free tools work around one: Find sources turns up the studies or texts to set side by side, Cite a source takes each reference from the publisher's record and screens it for retraction, Verify references checks the list, and Check your paper reads the brief into a checklist.
What does a compare and contrast essay ask you to do?
It asks for an argument that a comparison makes possible. The University of North Carolina at Chapel Hill Writing Center (n.d.) says these assignments push students past description towards analysis, and warns against a thesis that stops at two things being similar here and unlike there. Visvis and Plotnick (n.d.), writing for the University of Toronto, add that "compare" in a brief usually means similarities and differences both.
The subjects need enough in common to be worth setting together: Excelsior's writing lab offers a favourite television programme and a holiday destination as a pair that fails (Excelsior Online Writing Lab, n.d.). And the comparison needs a purpose; the University of Maryland Global Campus Effective Writing Center (n.d.) tells students to settle what it is for before outlining.
When the comparison is only part of the task
Some briefs never say compare. UNC's examples include how two Romantic poems treat one theme, and a comparison followed by which account is more accurate. There the comparison is the method and the evaluation is the task. How to read an assignment brief covers the wider reading.
How do you choose the grounds of comparison?
Choose grounds that apply to every subject and matter to the question. The University of Waterloo Writing and Communication Centre (n.d.) calls this the basis of comparison: a theme or category that fits all the items, with different details in each. Toronto notes that the question may supply it, as with the figure of the gentleman in two named novels, or leave it to you.
Start wide, then cut. UNC suggests a chart, grounds down the side and subjects across the top, then asks which grounds are relevant, interesting and useful to the argument. Its example: that two Romantic poems both treat nature is relevant but not revealing, since the class has probably discussed it already; how each depicts nature is the better ground. UMGC adds fair play: the same criteria for each subject, in the same order, with no evidence left out or inflated.
Block or point-by-point: which structure should you use?
Point-by-point when the subjects pair up closely; block when they share few matching points, or when there are more than two. Every guide we read names these two patterns.
| Structure | The shape | Suits | The risk | From |
|---|---|---|---|---|
| Point-by-point (alternating) | One ground per paragraph, both subjects in it | Closely paired points; longer or more complex analysis | In our view, swapping subject every sentence blurs | Toronto, UMGC, Saint Mary's |
| Point-by-point, paired paragraphs | For each ground, a paragraph on A, then one on B | More to say on each ground | In our view, B paragraphs that forget their A | UNC |
| Block (subject-by-subject) | All of A, then all of B, B referring back to A | Few related points; B builds on A; three or more subjects | Two separate essays under one introduction | Toronto, Waterloo, Saint Mary's |
| Mixed, or "lens" | A short block on the lens subject, then the main subject against it | One subject is a tool for reading the other | In our view, the lens block growing to half the essay | UNC |
| Any structure: finding what to compare | EdCitation's Find sources, by topic or by claim | Comparisons of published work | A search is not reading: open each work | This guide |
Where the guides disagree
On length they point opposite ways. Saint Mary's University Writing Centre and Academic Communications (2018) says writers generally use point-by-point for longer essays and block can suit shorter ones. UMGC ties the choice to complexity instead, and Waterloo favours block for setting something new against something traditional. Toronto's test is the most useful: if you can name closely related points about A and B, alternate; if you cannot, forcing it is counterproductive.
The split essay
The University of California, Berkeley, Student Learning Center (n.d.) names the failure block essays risk: all of Article A, all of Article B, then a short section of similarities at the end. Saint Mary's lists the same fault.
How do you write a thesis for a compare and contrast essay?
State what the comparison shows, and weigh it. Toronto tells students to decide whether similarities or differences carry more weight and to write a thesis reflecting that; its Darwin and Lamarck example grants a difference on whether acquired traits are inherited, then names what the two shared. Waterloo's template opens on shared characteristics and turns on "profound differences". Then ask UNC's question: so what? Saying two restaurants differ in atmosphere is specific; saying which suits a purpose, and why, is an argument.
Which transition words signal a comparison?
Words that name the relationship. The groups below are from the writing centres; what a word does in your sentence matters more than the list it came from.
- Similarity: similarly, likewise, in the same way, like, compared to (UNC; Vanderbilt University Writing Studio, n.d.; UMGC).
- Difference: however, in contrast, on the other hand, conversely, unlike, whereas (UNC, Vanderbilt, UMGC).
- Balance: on the one hand … on the other hand (UNC).
- Inside a block: "Unlike A, B …" or "Like A, B …" (Toronto); "In the same way" or "In contrast to" (Saint Mary's).
The lists disagree: Vanderbilt's comparison list includes "conversely" and "whereas", which the same handout also files under contrast and exception. More in signposting and linking words.
How do you compare theories, studies or texts in different subjects?
With grounds that belong to the discipline; the structure stays the same.
Texts in the humanities
A theme, figure, device or form. UNC's questions for two pieces of writing cover plot, characterisation, setting, theme, tone and narration. In Toronto's example, one novel defines the gentleman by morality, the other by hard work.
Theories in the social sciences
What each claims, the evidence usually offered, its scope and how it is applied, among UNC's questions for two theories. Saint Mary's model outline sets Mill against Bakunin on three democratic principles, a pair of paragraphs to each.
Studies in the sciences and social sciences
The question, population, design, measure, result and limitations, read past the abstract. Studies that seem to disagree often measured different things, and each must still stand, as the next section shows. Synthesis, not summary and critical writing cover weighing sources.
A worked example: one point-by-point paragraph on two real studies
This example is ours. The two studies are real, and every figure comes from the papers, read in full on Europe PMC. Our imagined essay argues that a sugar tax can only be judged against what it was designed to change; this paragraph takes the ground "what each study measured".
A sugar tax can only be judged by the outcome it was built to move, and these two evaluations measured different ones. Mexico's excise tax, one peso a litre from January 2014 on non-dairy, non-alcoholic drinks with added sugar, worked through price, so Colchero et al. (2016) asked whether households bought less: against pre-tax trends, purchases of taxed drinks fell by an average of 6% in 2014, and by 9% among households of low socioeconomic status. The UK levy, by contrast, charged manufacturers in two tiers by the sugar in each drink, and Rogers et al. (2023) describe it as explicitly designed to encourage reformulation. They therefore measured sugar as well as volume, and the two moved apart: a year after the levy began, households bought 2.6% more soft drinks overall, yet 2.7% less sugar in them. Both studies used household purchase panels and projected earlier trends forward, and neither covers every drink: Colchero et al. had no comparable data on purchases outside stores, and Rogers et al. counted only purchases brought into the home. Side by side, they show that "did the tax work?" has no single answer until one asks what the tax was for.
What the paragraph does
- One ground, both subjects. The topic sentence names the ground and the paragraph stays on it.
- The same questions of each: what was taxed, what was measured, what changed, against what.
- Transitions that name the relationship: "by contrast" for the turn, "both" and "neither" for the shared limits.
- A closing sentence that argues what neither study says alone. Rogers et al. make a narrower comparison of their own: unlike earlier studies from Mexico and Barbados, they saw no rise in bottled water bought.
The study we nearly used
Our first UK choice was Pell et al. (2021), which reported sugar in soft drinks down about 30 g, or 10%, per household per week, with volume unchanged. The BMJ (2023) retracted it in December 2023: the authors had found an error in how the data were prepared, and once it was corrected, the fall in sugar was smaller and the volume bought rose. Rogers et al. (2023) is the corrected study. Built on the retracted figures, our paragraph would have said volume held steady. To discuss a retracted paper, the American Psychological Association (2025) adds the retraction's year, journal and pages in parentheses after the original details; retracted papers in your reference list has more.
Compare and contrast essay, step by step
- Read the brief. Paste it into EdCitation's Check your paper, then read it yourself for the task.
- Find the subjects, if the brief leaves them open, in Find sources.
- Chart the grounds and cut to the few that serve the question.
- Weigh similarities against differences and write the thesis.
- Choose the structure by Toronto's test.
- Draft each paragraph on one ground, both subjects in it, ending on a claim.
- Build each reference in Cite a source and read any retraction notice it shows.
- Check the list in Verify references.
What did Check your paper read from a real comparison brief?
We pasted the essay guidelines and the first two sets of questions from MIT's Foundations of World Culture I (Hayek, 2011), 2,202 characters, into Check your paper on 26 September 2026. It returned three rules, each with its sentence:
- Page count: 7 to 8, from "respond to it in an essay of 7–8 pages".
- Line spacing: double, from the sentence asking for "a 12-type font" and double spacing.
- Citation style: MLA, from "Use the MLA guidelines for citation". Cite a source builds MLA 9 entries.
It set aside ten sentences for you to read, among them the demand for a thesis, both comparison tasks and the rules on revising. The 12-point size did not come back as a rule; its sentence was set aside as "A choice of font", so set the size yourself. Some question sentences, such as how the texts represent the duties of the individual, appeared in neither list. The checklist caught the format; which texts to compare, and on what grounds, stayed with the student.
How EdCitation helps with a compare and contrast essay
EdCitation is the best tool for the evidence behind a comparison, because it looks each reference up in the publisher's record and never writes one. That is what caught the retraction above: given the DOI of Pell et al. (2021), Cite a source flagged it as retracted and named the 2023 notice, which no chatbot composing a reference from memory can promise.
Free, with no account
- Find sources covers about 300 million published works; type a topic or the claim a sentence makes, then narrow by kind of source, years or open access. On 26 September 2026, "sugar-sweetened beverage tax" returned 252,064 results; by best match two preprints led, and Colchero et al. came 68th. Filtered to articles and sorted by most cited, it came first, cited 568 times. "Soft drinks industry levy", filtered the same way, put Rogers et al. fifth, and listed the Pell retraction notice. The claim "a tax on sugary drinks reduces the amount of sugar households buy" returned 426,648 results, led by a 2015 journal item and a 2013 magazine story, neither study in the first ten: a broad claim needs filters too.
- Cite a source takes a DOI, an ISBN, a PubMed ID, a title or a web address and sets the entry in any of six styles: APA 7, MLA 9, Harvard, IEEE, Vancouver, or Chicago 18 in its author-date form. Given 10.1136/bmjopen-2023-077059, its APA 7 entry read: Rogers, N. T., Pell, D., Mytton, O. T., Penney, T. L., Briggs, A., Cummins, S., Jones, C., Rayner, M., Rutter, H., Scarborough, P., Sharp, S., Smith, R., White, M., & Adams, J. (2023). Changes in soft drinks purchased by British households associated with the UK soft drinks industry levy: A controlled interrupted time series analysis. BMJ Open, 13(12), Article e077059. https://doi.org/10.1136/bmjopen-2023-077059. Nothing needed correcting: on the page the journal and volume are italic, and Sharp and Smith carry one initial each, as the article prints them.
- Verify references sorts a pasted list or uploaded paper into verified, doubtful ("check this") and not found, marks retractions, and keeps a lookup that failed as "could not check" rather than calling it not found. Given Colchero, Rogers and the retracted Pell entries, it verified all three records and counted one retraction.
Max
In the Max plan ($24 a month), Theoretics QA holds the finished essay up against the instructions of its own assignment, cites your sentences as its evidence, and changes none of them. The argument stays yours. Plans are on the pricing page.
Quick questions
What is the difference between block and point-by-point structure?
Block covers all of one subject, then all of the other; point-by-point takes one ground at a time and discusses both subjects on it. If the points pair closely, alternate.
How many paragraphs should a compare and contrast essay have?
One or more for each ground, plus an introduction and a conclusion. No guide we read sets a number; the word limit decides.
Should similarities and differences get equal space?
No. Weigh them, as Toronto advises, and let the thesis say which carries more weight and why.
Can I compare studies with different methods?
Yes, on shared grounds such as what each measured, saying where the methods limit the comparison. Check first that neither study has been corrected or retracted.
Can EdCitation write my compare and contrast essay?
No. EdCitation never writes any part of a paper. Find sources finds the works to compare, Cite a source builds their references and Check your paper reads the brief, all free.
References
- American Psychological Association. (2025). Journal article references. APA Style. https://apastyle.apa.org/style-grammar-guidelines/references/examples/journal-article-references
- The BMJ. (2023). RETRACTION: Changes in soft drinks purchased by British households associated with the UK soft drinks industry levy: controlled interrupted time series analysis. BMJ, 383, Article p2705. https://doi.org/10.1136/bmj.p2705
- Colchero, M. A., Popkin, B. M., Rivera, J. A., & Ng, S. W. (2016). Beverage purchases from stores in Mexico under the excise tax on sugar sweetened beverages: Observational study. BMJ, 352, Article h6704. https://doi.org/10.1136/bmj.h6704
- Excelsior Online Writing Lab. (n.d.). Compare & contrast essay. Excelsior University. https://owl.excelsior.edu/rhetorical-styles/compare-and-contrast-essay/
- Hayek, G. (2011). Assignments [Course materials]. 21L.001 Foundations of World Culture I: World Civilizations and Texts, MIT OpenCourseWare. https://ocw.mit.edu/courses/21l-001x-foundations-of-world-culture-i-world-civilizations-and-texts-fall-2011/pages/assignments/
- Pell, D., Mytton, O., Penney, T. L., Briggs, A., Cummins, S., Penn-Jones, C., Rayner, M., Rutter, H., Scarborough, P., Sharp, S. J., Smith, R. D., White, M., & Adams, J. (2021). Changes in soft drinks purchased by British households associated with the UK soft drinks industry levy: Controlled interrupted time series analysis. BMJ, 372, Article n254. https://doi.org/10.1136/bmj.n254 (Retraction published 2023, BMJ, 383, Article p2705)
- Rogers, N. T., Pell, D., Mytton, O. T., Penney, T. L., Briggs, A., Cummins, S., Jones, C., Rayner, M., Rutter, H., Scarborough, P., Sharp, S., Smith, R., White, M., & Adams, J. (2023). Changes in soft drinks purchased by British households associated with the UK soft drinks industry levy: A controlled interrupted time series analysis. BMJ Open, 13(12), Article e077059. https://doi.org/10.1136/bmjopen-2023-077059
- Saint Mary's University Writing Centre and Academic Communications. (2018, May 7). Compare and contrast essays. Centre for Excellence in Teaching and Learning. https://studio.smu.ca/ac-resources/compare-contrast-essays
- University of California, Berkeley, Student Learning Center. (n.d.). Comparing and contrasting. https://slc.berkeley.edu/writing-worksheets-and-other-writing-resources/comparing-and-contrasting
- University of Maryland Global Campus Effective Writing Center. (n.d.). Writing to compare or contrast. https://www.umgc.edu/current-students/learning-resources/writing-center/writing-resources/writing/writing-to-compare-or-contrast
- University of North Carolina at Chapel Hill Writing Center. (n.d.). Comparing and contrasting. https://writingcenter.unc.edu/tips-and-tools/comparing-and-contrasting/
- University of Waterloo Writing and Communication Centre. (n.d.). Comparative essays. https://uwaterloo.ca/writing-and-communication-centre/comparative-essays
- Vanderbilt University Writing Studio. (n.d.). Common transition words and phrases. https://www.vanderbilt.edu/writing/resources/handouts/transitions/
- Visvis, V., & Plotnick, J. (n.d.). The comparative essay. Writing Advice, University of Toronto. https://advice.writing.utoronto.ca/types-of-writing/comparative-essay/