I'm not sure it will help because I don't know if WebPA supports this  
scenario, but I can describe some known practice at MIT that addresses  
this issue. In the MIT example I know of, the project work is all done  
in lab space during lab hours. The instructor (and his teaching  
assistants) are available during the lab time and move around the lab  
observing and advising. At the end of the project, the instructor  
(with the teaching assistants) *subjectively* assigns a mark for the  
work - a mark that does not 'count' for the official mark. The Peer  
Assessment marks are then compared to the subjective instructor's mark  
and discrepancies investigated. He tells me there are few  
discrepancies and those that come up are readily resolved by  
consulting with the group.

It is possible that merely knowing this mechanism exists moderates  
behaviour.

But whether this is of use depends on the use scenario and whether the  
instructor has enough information to arrive at even a superficial/ 
subjective mark.

HTH, John

On 8 Dec 2008, at 11:01, Nicola Wilkinson wrote:

> I have received an email from Mike asking about selfishness within  
> WebPA. Can anyone help to answer his question (see the email text  
> below)
>
> Thanks
> Nic
>
> --------------------------------------------
> Nicola Wilkinson
> eLearning Systems Developer
> WebPA Project, engCETL
>
> Web: http://webpaproject.lboro.ac.uk/
> JISCmail: http://www.jiscmail.ac.uk/lists/webpa.html
> Project Blog: http://webpa-tec.blogspot.com/
> --------------------------------------------
>
> Hi there.
>
> 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.
>
> Thanks,
>
> Mike