My main interest was in establishing whether there was a dominant view rather than in grouping. The latter was meant to facilitate the discussion but if it is a hindrance I have no issue in dropping the classification altogether.
When you say "establishing whether there is a dominant view," do you mean you're interested in establishing whether the view of "the SCS belongs to China and the rest of the claimants are trespassing" is a dominant one?
I assume that this is what you mean, in which case, I do not know.
That specific view may well make up a meaningful fraction of the views that can be held on the forum regarding the SCS dispute, but it may not be dominant, as we'd also have to define what it means to be dominant.
I.e.: if over 50% of the members believe in it, then I think it could quite convincingly be considered a dominant view, or at least a majority view. But what if the question is phrased so that we have a dozen answers of differing grades of severity (which I think should be the most accurate way to determine this, given the specific view itself is lying on a continuum), and if only say 25% of the members hold that particular view and the rest are distributed smaller among the other views, then would that 25% still be considered "dominant"? It would definitely be the largest single view held by some of the population, but I'm not sure if 25% would be dominant per se.
These are all rhetorical questions of course, but it is demonstrating my belief, that the view you're looking to establish as dominant or not, is very much on a continuous scale between two extremes -- with those extremes roughly summed up as "the islands are completely china's and everyone else has no claim" on one end, and "china has no claim on the island's at all" on the other end.
Technically we can measure a continuous variable by using labelling the two extremes on a line and asking people to draw a mark as to where their view is between those two extremes, but that still won't really answer your question, in which case maybe it can be replaced with a number of short statements from one extreme to another and for people to tick one they most agree with.... and with one of the statements (likely at one extreme position) being "the SCS belongs to China and the rest of the claimants are trespassing".
....
Or are you just asking if any dominant view on this forum exists? A stupid example off the top of my head, is if we asked everyone on the forum what 1+1 is, hopefully they'd all say 2. In which case 1+1=2 is technically a dominant view.
I prefer self selection because if the main objective is to determine relative views than the aim is to go for as wide as possible the population regardless of whether that population is expressive or not.
I would be interested to hear your concern about bias and how it might affect the survey in terms of representation.
If the goal is to determine if a dominant view exists on this forum (or indeed, any group), then any survey naturally should be representative of the population via random selection. Self selection bias may skew the results if the representative sample does not display the actual proportions of the true population.
E.g.: people more invested in the discussion at hand might be more keen to answer a hypothetical survey, while people who are lurkers may not bother with it, but the views of those lurkers are also technically part of the actual forum's position as well. If we are only interested in the views of regular posting members then it may be viable to compile a list of those members and to ask all of them to answer a survey, and maybe randomly select a sample of those members.
Of course, even random selection of individuals may be susceptible to a degree of self selection bias because people can choose not to answer a survey even if they are randomly selected from a population, but that tends to be rare I think.