Teachers clearly communicate their expectations about writing to the students. In most cases, this will involve spending some class time addressing the art of writing. No one method of evaluating and responding to papers is mandated, however. Writing assignments play a role in determining the students' grades. It is assumed that the role of written work in determining students' grades will vary from course to course and from one discipline to another.
Assignments serve the particular purposes of the course.
Both assignments and the structure of the course are designed to help students to think critically and to express their judgments, both orally and in writing, in a responsible, logical, and persuasive fashion.