I use these evaluation forms when doing cooperative group projects. I have students fill out both; one reflecting upon themselves and one evaluating their group members. I do factor it into their grade for projects; 5-10 points for their self evaluation and 1-3 points for towards each group members grade, depending on if they were rated negative (1 point), check (2 points) or plus (3 points). I copy it front and back to save paper. I also keep the group evaluation "confidential" so students are honest about those that didn't cooperate or chip in as much as others.