Although details and examples can be used in all kinds of expository writing, not all essay topics are best developed in an example essay pattern.  Very often, for example, you are asked to compare and contrast two things, items, or people.  In your history class you might be asked to compare and contrast the Greek and Roman empires; in your biology class you might be required to compare and contrast DNA and RNA.  Comparing and contrasting is a process we all do every day.  We compare and contrast to determine the superiority of one thing over another.  When we buy a car, for instance, we usually shop around and compare deals.  We explain something that is unknown by comparing it to something that is known.  We might explain what a barometer is by saying it looks like a thermometer but measures atmospheric pressure instead of temperature.  We also compare and contrast when we want to show that two apparently similar things are in fact quite different in important ways, or to show that two apparently dissimilar things are really quite similar in significant ways.  It might, for instance, be quite enlightening to discover that two very different cultures have some important things in common.  We also compare and contrast to show how something or someone has changed, such as Mt. St. Helens before and after the volcano erupted.

We have many reasons for comparing and contrasting, and since comparison and contrasting is such a common method of thinking and of developing topics, it is important to write a well-organized comparison and contrast paper.  There is one thing to keep in mind, however.  With comparison and contrast, the purpose is not just to point out similarities and differences or advantages and disadvantages; the purpose is to persuade, explain, or inform.  Think of comparison and contrast as a method of development — not as a purpose for writing.

When you are planning a comparison and contrast essay, there are several points to consider.

Points of Comparison

Let us say that you were asked to compare and contrast two people — perhaps two generals, two politicians, or two religious leaders.  What would you compare and contrast about them?  You could compare their looks, backgrounds, philosophies, the way they treat people, their attitudes toward life, their intelligence, their life styles, and so on.  The list could continue, but this is just the problem:  you would have a list.  When comparing and contrasting two things, people, countries, and so forth, especially for a standard 300-to 500-word essay, it is best to restrict the points of comparison to two to four.  Therefore, be selective and choose the most significant points for comparison that would support the central idea in your essay.  For instance, if you were comparing two politicians in order to show that one is better as a public servant, you would not bother with comparing and contrasting their tastes in food; it would be irrelevant.

Emphasis on Comparison or Contrast

             In a comparison and contrast essay, the emphasis is usually on one or the other; in other words, you spend more time comparing or contrasting, depending on your purpose.  If you are comparing two rather similar things, acknowledge the obvious similarities, but focus on the differences.  If you are comparing two obviously dissimilar things, acknowledge the obvious contrast, but again, emphasize the less obvious similarities.

A comparison is a systematic strategy for analyzing and evaluating the similarities of two or more things.  (A contrast is simply a comparison that emphasizes differences rather than similarities.)  An effective comparison attempts to demonstrate one of three general purposes:

  • Two things thought to be different are actually similar.
  • Two things thought to be similar are really quite different.
  • Two things, although comparable, are not equal – that is, one is better than the other.