2008/11/1 Thomas Dalton thomas.dalton@gmail.com:
It's the people that stopped answering questions completely just before the language questions that are the problem
Sure. But before we actually look at the data (which will tell us that, too), I would be careful speculating about the extent of bias in each question. In any event, any survey is always an approximation of the truth -- just ask the US election pollsters. :-)