Given the three options offered, all suboptimal, it is unsurprising that people choose something like this. But if you want a fair survey, the 'outcome' should still be compared with the status quo (which may be preferable to people): semi-rotational scheme, every year with some level of bidding possibility. Because even when you take this survey as your basis, the differences were not that big (61 vs 52% in favour for biannual vs fixed rotation every year). 

Anyway, check out the page, there are some interesting thoughts out there, and I'm looking forward to step two after Esino Lario, when we know the outcomes of the experiments there. 

Lodewijk

(not connected to this survey)