Grading Without Points: Does It Hurt Student Performance?
We gave students enrolled in a research methods course the option of receiving normal grade feedback on assignments (with point values assigned) or receiving feedback on assignments without point values assigned. With respect to final grades earned, students in the two groups did not differ significantly. Final grades were related to self-report of effort as well as future career plans. We encourage instructors to experiment with the mechanics of grade feedback to optimize educational opportunities for students.
Landrum, R. Eric and Dietz, Karen H.. (2006). "Grading Without Points: Does It Hurt Student Performance?". College Teaching, 54(4), 298-301.