This is the dilemma of self and peer assessment - should you give them control (when control inevitably leaves it open to this kind of abuse. Having had experience of WebPA for over 10 years, here is my take on it in bullet form.
1) Using Web-PA you only allow students partial control - because you can check (and query if necessary all results that you think are erroneous after the marking is submitted). Normally very little, if any editing is required.
2) When I introduce Web-PA I always make it clear that marking is anonymous except that the only other person who will see the detailed breakdown is ME! I am careful to advise them that their marks are likely to be monitored.
3) It is true that weak students generally overplay their contribution but it is also just as true that other members of a team with a weak student tend to be over-critical of him/her and mark them perhaps lower than is justified. The scenario you paint is rare in my experience and could probably be picked up prior to final publication.
4) There is an academic case that students undergoing teamwork have a responsibility for the cohesion of the team. t Hence a mechanism for moderating the overoptimistic or downright inaccurate scores of a weak student and for the potentially vindictive scores of peer members is a good thing and Web-Pa effectively provides that through self and peer assessment.
5) The main drivers for this imperfect, yet sound solution are - a) to give the students responsibility and make them think about what is good and bad work b) I have not yet found a better solution to group marking and c) there is much evidence that the students who use this system and generally more content than with other systems.
Have a look at my paper on this at http://www.engsc.ac.uk/journal/index.php/ee/issue/view/21
At the end of the day, the decision is yours.
From: WebPA Project [mailto:[log in to unmask]] On Behalf Of Nicola Wilkinson
Sent: 08 December 2008 11:01
To: [log in to unmask]
I have received an email from Mike asking about selfishness within WebPA. Can anyone help to answer his question (see the email text below)
eLearning Systems Developer
WebPA Project, engCETL
Project Blog: http://webpa-tec.blogspot.com/
I'm very interested in the WebPA system but I have been looking over the
documentation and I can't see any way of preventing students from selfishly
manipulating marks to boost there own scores. Is there a mechanism that you
haven't explained in the demonstrations, or is the only solution to prevent
students from assessing themselves (something I don't want to do)?
What I mean is, say a report for a 4-person group got 80%, and I had
decided to use a 40% PA weighting. Therefore, each student effectively
controls a 10% stake of their 80% mark. What is to prevent one of them from
marking themselves 5/5 on every criterion and their peers 1/5? Assuming the
other scores were completely even, this would give them a webPA score of
1.375. 1.375 x 40% = 55%, giving a total score for the selfish student of
95% and scores for the others of 0.875 x 40% + 40% = 75%. Essentially, the
selfish student has taken 5% from each of the others. Is there a flag to
alert the assessor of this? In this example it would be fairly obvious, but
I imagine that when the other numbers vary it would be easy to miss that.