Political Survey: Rationale

politicalcompass.org is a web site which asks a number of opinion questions of its visitors, and then places them in a two-dimensional space which is supposed to characterise their political views. Unfortunately, politicalcompass.org has a poor reputation; in particular, there is a suspicion that its questions are designed to make respondents lean towards an economically right-wing, socially liberal ("right libertarian") position, and the two axes of variation on which results are plotted are opaque in their derivation and may not be tremendously relevant.

These suspicions are compounded by the problem that politicalcompass.org's methods are not open and, therefore, it is not possible to determine whether their selection of questions carries a bias which its operators are using to further their own ends.

The purpose of this site is to do a survey of this type properly and openly, so that the methods and data in use are open to inspection.

More detail

The proper way to do this is to collect a bunch of questions and a bunch of answers to them, then take the space defined by all the answers to the questions, and construct a spanning basis for it. The natural way to do this is with principal components analysis, though as a non-statistician I can't comment on whether this is actually the best approach. We should then be able to discover -- in terms defined by the answers to the questions set -- the significant axes of variation in the data.

This means that all the results we get are defined by the data: we do not measure anyone's views according to criteria we set out, but according to endogenous criteria. The only points at which our judgment enters the method are

The first of those shouldn't matter, if the questions are reasonably unbiased and cover a wide enough range of subject materials. The second doesn't matter, since it's just a presentational issue.

I'll write a bit more about this later, but for now, here are some notes about the process.


Openness requires that the source code for the software which runs the site, and the data from which the principal axes were computed, be available. You can get both from the internals page.

Political Survey: an open, honest version of politicalcompass.org.
Copyright 2003 Chris Lightfoot. Available under a Creative Commons Licence.
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