Writing topic sentences
for compare and contrast exposition

In a compare-contrast essay plan, a topic sentence that says X and Y are identical, similar, or totally unlike with regard to a characteristic is not adequate.

Body paragraphs of C&C essays require summarizing sentences that:

1. Sum up the content of the paragraph, and

2. Indicate the paragraph content supports the essay's thesis statement.

Without instruction in how to plan a C&C essay, students typically mess up.

Show of thesis support is essential

Left on their own, students come up sentences that are simply facts, such as these:

• Community colleges offer associate degrees; four-year colleges offer bachelors' degrees.

• Community colleges and four-year colleges offer different types of degrees.

Such sentences may be accurate summaries of the paragraph content, but they do not reveal how the content supports their thesis.

Topic-thesis sentence relationship

I teach students to assemble a writing skeleton™ from using a few graphic organizers that function as data collection units with built-in user directions.

For compare-contrast writing, the graphic organizer I use as the basis for building a thesis statement is:

You can compare that to the graphic organizer for the thesis of a single-topic expository essay.

Using that C&C graphic organizer helps students come up with a thesis statement like this:

Community colleges are a better choice for average students than four-year colleges.

Students build on their thesis statements in exactly the same way they do for single-topic essays:

Substituting their content for the items shown produces topic sentences for the expository body paragraphs. Click to see the sample writing skeleton™ on this thesis.

Best practice: activate knowledge

If you want students to write comparison essays that actually analyze a relationship between two items, you need to begin with what students already know.

Students are already familiar with the comparison process. They just need someone to point out how they can use the same procedures with a compare and contrast topic that they use outside class.