As part of the protocol, students in the experimental group had to write a rationale each time they self-evaluated, pointing to the features of their work that supported their ratings. In addition, students used the criteria to give feedback to classmates when projects were presented orally in class. Compared to controls, students who had participated in self-assessment produced projects that were much more highly rated by their teachers (on the shared criteria). In addition, initially low –achieving students showed dramatic gains on a measure o f conceptual understanding.