In addition to the standard census questions I think it would be good to have an optional page two that asks for agreement with various statements about rationality. I think it would be very interesting to see how many different dimensions there are in our disaggrements.
One of the statements might be:
It's useful to identify oneself as an aspiring rationalist.
Some people in our community like labels like that while other find them annoying.
Given that it's been a while since the last survey (http://lesswrong.com/lw/lhg/2014_survey_results/)
It's now time to open the floor to suggestions of improvements to the last survey. If you have a question you think should be on the survey (perhaps with reasons why, predictions as to the result, or other useful commentary about a survey question)
Alternatively questions that should not be included in the next survey, with similar reasons as to why...
survey is now up (2016-03-26) http://lesswrong.com/lw/nfk/lesswrong_2016_survey/