Within the collaborative IF classroom, sanctuary is emphasized. Students will be most open when the feel safe. And the most compelling fear among this generation of students is that they will be publicly belittled by peers. This can make the idea of doing peer evaluations daunting.
In fact, though, peer evaluations can provide a tremendous opportunity for student growth– both for the evaluated students and the evaluator, as well. I have found that it is most helpful that peer evaluations be reviewed by the professor before they are submitted to the facilitator. In nearly every class I have taught, there is usually one student who is especially marginalized. Fellow students will often snicker behind the student’s back, and no one wants to “end up” in a group with such a student. Personally, I wouldn’t have wanted to be in that group myself. Students that are grouped with a student who is just plain different (one year, I had a student start transitioning from a man to a pre-op transsexual woman…that was when I started using a circle formation with even 70 students in a class because I grew so tired of the snickering by students in the back of the classroom) or a student who lacks competent interaction skills (s/he might interrupt frequently, display anger or sulking behavior when s/he feel an idea is being ignored, etc.) may see a peer evaluation as an opportunity to finally speak their mind to this student.
If you use anonymous peer evaluations, there is that much more of a risk that students will be mean-spirited. If you used signed evaluations, everyone will just write some benign pabulum that will help no one. Ideally, what you want is for the students to be candid but professional– and this is an important and valuable skill for them to learn. You want them to give the criticism to the troubled student, but you want them to do it in a constructive manner. And so, having them first give their comments to you and then either compiling those comments into a summary document for the evaluated student or just forwarding the comments along solves a lot of these problems because it gives you a chance to read the initial comments from group members (what they’d like to say to the difficult group mate) and then to help them think about how they can say what they want to say in a constructive manner. This then opens the chance to discuss what constructive criticism looks like and why its important (this is also something one could talk some about to the whole class in advance of students doing a peer evaluation).
The challenge with all this is, of course, that it takes time. I do not do an extensive amount of peer evaluation for just this reason. However, I find that letting the students do it once per person during, maybe, the second time each person facilitates or even having the students do a group evaluation midway through the semester in which they evaluate each member of the group, including themselves, in terms of their contribution/interaction style/facilitation (if relevant, as yet).
Hope that this was helpful. As always, I remain willing to talk with anyone about evaluation approaches, from the conceptual to the practical.