In all academic disciplines college teachers respond to student writing with shortcuts--checksheets, correction symbols, computer style checkers, etc. But while these methods save teachers time, do they help students improve their writing? A survey of research into teacher commentary, conceived of as a contextual discourse activity, initially questions the efficiency of many shortcuts because it finds complexities in all activity areas, in regulation (criteria, rules of genre and mode, disciplinary styles, and standards), consumption, production, representation, and identity. The research, however, also recommends particular shortcuts and methods of revising them for better efficiency and effect. It especially recommends restricting the volume of teacher commentary in ways that are task, discipline, and learner specific.