In summative assessment the same mark could be given to each member of a group or individual members could have an opportunity to gain different marks. I adopt the latter approach by combining tutor and peer assessment. See, however, Savin-Baden (2004, A briefing on assessment in PBL, listed in the web links provided in Section 6) for a summary of the various assessment tools that may be used in a PBL context.
After some trial and error, I have adopted a method of assessment in which the tutor provides an initial total mark for the group response (either a presentation or written report). The maximum mark to be awarded by the tutor is 100 multiplied by the number of group members. A group with six members therefore earns a maximum of 600. The mark awarded to the group is accompanied by written and oral feedback. If the tutor rates the group’s response as worthy of 60 per cent (using assessment criteria contained in the PBL handbook given to students), the group is awarded a total of 360 marks.
The group then has to decide how to allocate the 360 marks amongst the members of the group, with the proviso that no member can be awarded more than 100 marks. If the group decides that all members contributed equally, each member gets the same percentage mark provided by the teacher (60 per cent in this case). Groups can withhold marks from non-contributing members (either totally or partially). This could mean that not all marks are distributed within a difficult group. In this way, working members of the group can still earn good marks, but at the expense of non-working members. This assessment process takes place after each task is completed and each individual’s mark is recorded. For summative coursework purposes, each student is given an average mark taken over all the PBL tasks for the module.
If the PBL response is in written form, I advise groups not to indicate which members were responsible for each element of the final report. This allows the teacher to mark objectively without embarrassing particular group members whose contribution may have been weak.
All group work is open to difficulties created by ‘free-riders’. In my experience this has tended to arise with first-year students who have yet to establish appropriate work regimes, with the effect that they regularly missed one of the two meetings per PBL task. This, of course, introduced a disruptive element into the PBL group and it is particularly important that non-workers in a PBL environment are severely penalised whilst workers are fully rewarded. My approach to this problem has been to introduce a number of strict conditions that are clearly stipulated in the module handbook. These conditions are:
Experience at the University of Ulster suggests that when students are informed about these conditions at the start of their course, poor discipline is largely removed. The problem of free riding has not been apparent with final-year students.
Ensure that non-working members of the team are severely penalised while working members are fully rewarded.