Body paragraphs of comparison essays require topic sentences
that:
- Sum up the content of the paragraph, and
- Indicate the paragraph content
supports the essay's thesis statement.
Without instruction in how to plan a comparison essay, students
typically mess up.
On this page, we'll look at what how students' misunderstanding
of what comparisons should do leads them to mess up. Then we'll
look at how we brilliant teachers can clear up the confusion with
a wave of our magic pencils and have our darlings writing brilliant
comparisons by nightfall.
Show support for thesis
Left on their own, students come up with sentences that are simply
facts, such as these:
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.