I have read about this and other have told me about this it must be one of the worst ideas any company in the UK have ever come up with.
I work in school and we mark the optional sats in school. These papaers are like all other exam papers each child put their name on the front page only. So if someone splits the questions teh chances of a child being given wrong marks has just doubled.
I am still looking for more news posts on this subject but I really do not trust this method of marking.