Writing is a form of thinking
For me, writing is not just an end product of research - it is a step in thinking through an idea. In my teaching, I stress writing as a process - a thinking process - and my classes emphasize various forms of writing (graded and ungraded). Response papers are an important part of learning the material, and are chances for students to interact with both me and the ideas and ethnographies that they are reading; they are ungraded, and can be seen as reflections or notes that are submitted to me. I also use them to gauge people's reaction to the material, and are important in my improving classes so they address student's needs.
In more formal writing assignments (such as review essays, expository essays, and research papers), I look for strong arguments with a well-stated thesis, abundant presentation of specific theoretical or ethnographic evidence, and well-written (grammatically and structurally) prose. For more insight on how I judge papers, see my "Guide to Making an Argument" and "Thesis Statements."
I do take drafts, and in upper-level seminars I incorporate proposals, outlines, drafts for formal submission as part of student assessment. Remember to give me adequate time (one week prior to due date) to comment on your drafts.