[mkingston]

I was swayed by the argument against working in pairs, then swayed back by your argument in favour of working in pairs. I think the key part that changed my mind was "two students that get along well with each other". I wonder if you emphasise this in your instructions to students? And if so, how?

[enriquto]

We just let them group themselves. If there's an odd number of students, a group of three is allowed. Every couple of years there's a "bad experience", in which one of the students does all the work, or some kind of conflict. But so far it seems to be a good choice overall (after the deal, the students generally say that it was a happy experience).