Many teachers use grades as a weapon or a defense--not as the powerful learning tool they can be. A grading system in which students write papers over and over until they are fully acceptable, and in which they earn checkmarks for each piece of work accepted, serves as a powerful motivator. The checkmark system adheres to six primary learning principles: the problem--in this case, to write acceptable papers--appears genuine to students; motivation is intense and continuous; students know their rate of progress; they are not permitted to develop incorrect habits; they face challenges and successfully reach goals; and they work at their own individual speeds. Although the number of papers handled by teachers increases with this method, it is easier for teachers to grade the papers, since the emphasis is on helping students improve their work rather than on justifying an assigned grade; and although problems may arise that must be worked out by teachers, this grading system, on the whole has great advantages for both teachers and students. (GW)