Whether we make a “pros” and “cons” list about a major life event or try to decide which brand of peanut butter we’re going to buy, we constantly compare and contrast ideas and items in our lives. When we compare, we examine the similarities between things; when we contrast, we examine the differences between things.
What, exactly, is a comparison-contrast essay composed of? What do you need to think about when doing one? Well, there are several things to think about.

First, you need to decide on a purpose. Why are you making a comparison and/or contrast? It isn’t enough to just compare and contrast two or more things. You have to do that with some point in mind. For example, you might want to showthat two things are more similar (or different) than previously thought, or you might want to definetwo shades of an emotion or condition (such as happiness versus ecstasy); or you might want to dramatize the effectsof drinking one glass of red wine at dinner, for good health, versus drinking a case of red wine at dinner, with the ill effects of such an action; or you might want to persuadereaders that stricter divorce laws are needed by comparing the laws of several different states. Regardless of the purpose, you must compare and contrast with a purpose in mind. That purpose is one of the things that directs your essay. The other thing that directs your essay is your audience – for whom are you writing? What special knowledge do they have or lack? What special language do they use (jargon)?

Second, you need to make sure that the two (or more) things you’re comparing or contrasting are at least somewhat similar. You can, for example, compare a Ford and a Volvo because they’re both cars. You could not compare a car with a lawnmower (with the possible exception of an old Volkswagen). So, they need to have some related parts.

Third, you need to stay focused on your purpose. That is, you may want to inform (to present information as objectively as possible); to evaluate (as in pros and cons, with the goal of making some sort of judgment); to persuade (readers to take some action based upon your presentation of similarities or differences): to clear up misconceptions (by revealing previously hidden or misunderstood similarities or differences): or to draw an analogy between two seemingly unrelated subjects (such as a singles bar and a day at the zoo).

Fourth, you need to come up with a strong thesis. Now, a thesis always states the subject under discussion and the author’s perspective, treatment of the subject, or point of view. In a comparison-contrast essay, a thesis must do a few more things. It should name the subjects being compared and contrasted; it should indicate whether the focus is on the similarities, the differences, or both; and it should state the main point of comparison or contrast.

Fifth, you need to select the points to be discussed. Consider your audience when doing this. Be aware of what your readers know, what they don’t know, and what you can predict about their reactions. This should influence your choices of what to include. Of course, all of your points should support your thesis.

Sixth, organize your discussion. For a comparison-contrast essay, there are basically two ways to organize your material. They are:

The one-side-at-a-time (sometimes called the “block”) method, which is organized like this:

Introduction

Subject “A” – point 1

– point 2
– point 3, etc.
2. Subject “B” – point 1
– point 2
– point 3, etc.

Conclusion

Note that the points discussed are the same and in the same order. That makes for an easy comparison. This type of organization is best used for shorter, simpler essays.
Then there’s the point-by-point method, which is best used for longer, more complicated essays. It is organized like this:

Introduction

Point 1 – subject “A” then subject “B”

2. Point 2 – subject “A” then subject “B”
3. Point 3 – subject “A” then subject “B”, etc.

Conclusion

Lastly, be aware of language, as always. In order to make sure that the reader understands the comparisons and contrasts that you’re making, you need to make sure that you’re clear. Part of what makes this essay clear is good use of transitions, such as “also,” “in the same way,” “on the other hand,” or “likewise.”

The Assignment:
Please write a comparison-contrast essay that focuses on ONE of the following topics. Each of these will require a bit of research, so please plan to use and cite at least two sources.

Scientific versus religious ethical views on genetic engineering of humans
Various methods of determining, studying, and cataloging genetic ancestry
Different marriage structures and customs around the world
Different formal (and perhaps informal) caste or class systems around the world
Various energy sources being used or developed
Different military, paramilitary, or mercenary organizations within the USA
Various forms of space travel (focusing on propulsion) used or developed

Formatting:
Your essay should, as usual, conform to the following format.

4 or more pages in length, plus a Works Cited page
A Works Cited page
Use of at least two sources beyond our novel
A reference, a connection, to our novel Friday
MLA format, please