Teachers know that not everything they write on students’ papers leads to effective revision.  A recent study in the International Journal of Teaching and Learning in Higher Education indicates that teacher feedback is more likely to lead students to improve their writing when it is clear and direct; offers specific, local examples to support global comments; emphasizes content over grammar and mechanics; and occurs in writing that students have an investment in improving.

[Vardi, I. (2010). The relationship between feedback and change in tertiary student writing in the disciplines. International Journal of Teaching and Learning in Higher Education, 20(3), 350–361.]