weirdquark has correctly interpreted what I was trying to say.

Lignota--correct me if I'm wrong--seems to think that gaudior left option z out of the poll so that the poll could seem to be unbiased while actually containing a clear bias.

Not really. I don't think gaudior would play games like that.

I admit I phrased my first comment non-neutrally, because I was frustrated that (as I saw it) gaudior's ideological bias was causing her to miss something that seemed obvious to me.

I'm not actually expecting gaudior to conduct a survey with perfect scientific rigor here, and so I'm not personally that worried by the skewed-data issue. I think the comparison to SurveyFail is unfair. My concern is more that I think the implicit model behind gaudior's poll is faulty, and that if she wanted her poll to describe/capture the range of opinions about same-sex marriage and civil unions, she should have put a little more thought into it, including how to describe the range of opinions that she does not agree with but that people nonetheless hold.