The choices for writing or assigning a compare and contrast essay are almost endless.
Once the topic or the essay is assigned or chosen, brainstorm the qualities of each subject, then move on to some prewriting.
In a science course, topics could be based on comparing and contrasting two species of plants or animals, or comparing one theory in a given subject area to another theory.
Within a history course, an instructor could assign an essay that compares two historical figures, two time periods, two wars, or even two types of government.
When a writer contrasts two things, he or she explains ways in which they are different.