When students write in courses across the curriculum, they come to see writing as a worthwhile and necessary skill, something that educated people do. Continual practice in writing can also help them maintain and improve their writing abilities. Content-area teachers are uniquely able to teach their students, particularly upper-level students, to write in the "language" of their disciplines. Biology students, social science students, history students can become comfortable with the forms and vocabulary (and hence, thought processes) of biologists, social scientists, historians
Different writing activities accomplish different ends. A writing assignment should fit your purposes and help you meet your educational goals.
There are many reasons to have your students write, but overall goals can be grouped into writing to learn which can help students understand and retain course information writing to demonstrate knowledge through which students show that they have learned necessary information, and writing to improve or maintain writing skills in which style and correctness are important, . Most writing assignments serve more than one of these purposes concurrently.