Properly interpreting this data is hard. For instance, the relation between 'Desktop OS' and 'Compensation' suggests Windows 8 users earn significantly more, on average, than Linux users. However, if you dig a bit further, you find that Linux use is much higher in countries where 'Compensation' is much lower across the board. So the relationship between 'Desktop OS' and 'Compensation' is a proxy for the relationship between 'Country' and 'Compensation', which makes it much less surprising.
Agreed. Right now the best way to handle that is to filter your analysis in a way that accounts for confounding variables. So in the example you gave, you'd run the Desktop OS vs. Compensation analysis then filter for Country == USA only.
That's a pretty rough way to deal with that issue. Ideally you'd run a regression that more subtly takes country into account, without losing data. Unfortunately that's not possible in Statwing (currently...).
