I am organising and conducting the exercises for a graduate course. The exercises mainly exist to give the students the opportunity to learn by doing. However, the students also need to participate to some extent to be admitted to a final exam. Exercises are given out as homework one week before the class. During the class, students present their solutions to the exercises, which are discussed by other students and me. We evaluate this as follows (which is mostly standard at my university):
At the beginning of each exercise class, a paper containing student names and the numbers of the exercises is passed around and each student checks those those tasks for which they feel that they can present a reasonable attempt to solve it. This attempt does not need to be complete or correct; they should just be able to show what they tried and, if they failed, elaborate where they are stuck.
During the exercise class, the student presenting a given task is selected at random from those who checked it.
Tasks are so small that most of them cannot be reasonably divided into subtasks. (This should reduce the uncertainty how to report when only half of a task was attempted.)
To be admitted to the final exam, a student has to have checked at least half of all tasks. There is no benefit for students who have checked more exercises.
Mainly, the system seems to be working well: I haven’t spotted an overly optimistic self-report yet and I currently expect that 0.3 students will fail the exercise criterion.
My biggest issue with this system is that there is a huge variation amongst students regarding how optimistic or pessimistic their self-assessment is. In particular the system can make life more difficult for pessimistic students. For example it happened that a student who (legitimately) checked a task and was chosen to present her attempt was stuck at some point, and another student volunteered to help out even though he did not check the task.
Hence I am asking: Is there anything I can do to effect less variability in these self-reports? In particular, I would like to flatten the pessimistic side of the spectrum.
And just because somebody is bound to remark that life is harsh and the pessimistic students need to be more optimistic anyway: Yes, but I may be able to help them learn this.