To Write a Comparison-Contrast Essay

  1. Question the situation.
    • Subject: What topics will you compare and contrast?
    • Purpose: Why are you comparing these topics? What is your goal?
    • Audience: Who will read this essay? What do they need to know?
  2. Plan your essay.
    • Identify two specific topics to compare and contrast.
    • List your prior knowledge about these topics.
    • Project what you’d like to find out about each topic.
  3. Research your topics.
    • Searching: Consult primary and secondary sources. (See pages 376–389.) Consider using a T-chart to organize details about the two subjects.
    • Focusing: Decide on a focus and write the thesis statement, naming the two topics and summing up how they are similar and different.
    • Shaping: List key similarities and differences. Consider using a Venn diagram.
  4. Create the first draft of your essay.
    • Begin by introducing the topics and stating your thesis about their similarities or differences.
    • Follow with middle paragraphs that explain how the topics are similar or different.
    • Organize each paragraph using a point-by-point, subject-by-subject, or similarities-and-differences pattern (see page 462).
    • End with a paragraph that summarizes the comparison and contrast.
  5. Improve your first draft.
    • Evaluate your first draft.

      Subject: Are the two topics given equal attention? Does the comparison make sense and have worth?

      Purpose: Does the essay achieve your goal?

    • Revise your writing.

      Rewrite parts that are confusing or unclear.

      Add details to explain the comparison more fully.

      Cut unnecessary details.

    • Edit your writing.

      Check your writing for accuracy using pages 190–195 as a guide.

  6. Present the final copy of your essay to your instructor or post it on a relevant blog or wiki.

Comparison-Contrast Essay

In the following comparison-contrast essay, a student uses a point-by-point comparison to explore nuclear power and wind power.

Nuclear Versus Wind Power

The beginning introduces the two topics of comparison and includes a thesis statement (underlined).

Human beings have spent thousands of years burning things to make energy, but that strategy needs to change. Fossil fuel supplies are limited, they’re becoming increasingly expensive, and burning them is harmful to the environment. Two energy systems have emerged as potential replacements for fossil fuels—nuclear power and wind power. Which is preferable? Politicians, energy experts, and environmentalists disagree. While nuclear power is the more efficient system, wind power is the cleaner and more cost-effective alternative.

The middle paragraphs focus on different points of comparison.

In terms of the environmental impact, both wind and nuclear energy are cleaner options than fossil fuels. Neither wind nor nuclear energy emits harmful greenhouse gases that trap sunlight. As a result, they both benefit the atmosphere by reducing the danger of climate change, compared with fossil fuels. But wind power is cleaner than nuclear power because it uses a completely natural resource and has low environmental impact. (It harms some bird populations.) Conversely, nuclear power produces radioactive waste that must be contained in massive concrete structures or stored far underground. Nuclear disasters such as the one at Fukushima cause great environmental harm (Keeley).

Wind power is also more cost-effective than nuclear power. In 2011 the Energy Information Administration published an inflation-adjusted cost comparison for building and operating different types of energy plants over their life cycles. The report concluded that a state-of-the-art nuclear plant would cost $113.90 per MW-h (unit of energy equal to 1,000 kilowatt hours), while an onshore wind farm would cost $97 per MW-h. According to this report, wind energy is 15 percent cheaper than nuclear energy. For one thing, the upfront cost for building a nuclear plant with the appropriate emergency and containment systems is higher than the upfront cost for building a wind farm. For another, it costs 46 cents per MW-h to fuel a nuclear power plant, while the wind used to “fuel” a wind farm costs nothing (Koyama).


However, while wind is cleaner and cheaper than nuclear power, nuclear power production is more efficient, consistent, and flexible—better able to meet sudden jumps in energy demands. This is not surprising, as wind turbines spin only when the wind is blowing. And it is difficult to predict when the wind will blow and at what force. Even in the United States, which has greater wind potential than most places, wind turbines operate at about 33 percent capacity. Meanwhile, nuclear plants operate at 90 percent capacity at least. On average then, a wind farm takes two to three times longer to produce the same amount of energy that a nuclear power plant of the same capacity can produce (Koyama).

The ending paragraph summarizes the comparison.

Nuclear power and wind power are both environmentally friendly energy alternatives to fossil fuels, but they are substantially different from one another. While wind power is the cleaner, more cost-effective energy source, it is inconsistent in its efficiency and energy output. While nuclear power is more efficient and produces the greater volume of energy within a certain time frame, it comes with the additional safety concerns of radioactive waste and nuclear meltdowns. These differences have made it difficult for those concerned with energy production to agree on how to move away from fossil fuels . . . and still meet the general public’s energy needs.


Organizing Comparison-Contrast Essays

Point by Point
Subject by Subject
Similarities and Differences

Additional Resources