In my Media Design classes, peer critique is a very important learning component. I encourage students to honestly evaluate their classmates' work. In spite of my best efforts, students are normally reluctant to share honestly. In the past, some have not participated at all.
That has all changed since I implemented "Critique Participation Cards"; (CPC). A reusable CPC card is made and given to each student. The card has their name and class number on it. Anytime during the crit, when I feel that the student has sufficiently participated, I will collect their card. The card counts for a significant part of their grade. When the crit ends, no more cards are collected. If the student still holds their CPC when class ends, then they lose their CPC points. It is fun and a kind of game for some students. It works with all students.
If you would like more information, or have a question on Peer Critique, you can e-mail Randy Livingston at: email@example.com.