Another twist that I add to the small group discussion helps to take the
pressure of assessing off the teacher and put it on the students. Give each
group a given number of points to divide depending upon how much each student
contributed to the discussion or project. For example, a group of 4 students
might have 40 points to assign. A group of 5 has 50. At the end of each
discussion or work session they submit the grades to me for recording. With
my limited choice novel unit students have usually self-selected the degree
of difficulty of the novel and are fairly well matched according to ability
which avoids obvious fairness issues. I've had a lot of success with this.