Types of Purpose
Don Zimmerman, Journalism and Technical Communication Department
I look at most scientific and technical writing as being either informational or instructional in purpose. A third category is documentation for legal purposes. Most writing can be organized in one of these three ways. For example, an informational purpose is frequently used to make decisions. Memos, in most circles, carry key information.
When we communicate with other people, we are usually guided by some purpose, goal, or aim. We may want to express our feelings. We may want simply to explore an idea or perhaps entertain or amuse our listeners or readers. We may wish to inform people or explain an idea. We may wish to argue for or against an idea in order to persuade others to believe or act in a certain way. We make special kinds of arguments when we are evaluating or problem solving. Finally, we may wish to mediate or negotiate a solution in a tense or difficult situation.
Remember, however, that often writers combine purposes in a single piece of writing. Thus, we may, in a business report, begin by informing readers of the economic facts before we try to persuade them to take a certain course of action.