Developing a paragraph through the rhetorical use of elimination is a variation on the pattern of paragraph development by definition. Rather than defining what the subject is, a paragraph developed by elimination tells readers what the subject is not. The paragraph proceeds by defining classes of which its subject is not a member and then describes and summarizes examples in each class.
Definition by negation defining what something is not — is a very focused way to control meaning by setting apart an idea or object before defining what it is. Paragraphs developed by elimination are structured the same way as definition paragraphs.
One schema, from “Writing a Definition Paragraph,” describes three stages: a statement of the subject being defined, classification of the term and a brief description of the subject. To adjust this schema to develop a definition using elimination, once you state the subject, classify it by what it is not and use this classification to describe what the subject is not.
According to “The Mayfield Handbook of Technical & Scientific Writing,” the use of development by definition is important to “set [up] working generalizations” to define important terms and establish parameters of discussion. Since the purpose of definition is to separate ideas or terminology from other closely related subjects, development by elimination is often used in academic and other technical discussions to guide professional debate.