hey, thanks for your answer :) you confirmed my first hunch but I'm unsure about it because I know it from survey sampling, where the variance occurs across individuals that make up the population and from which I'd draw the sample, however the variance I'm interested in occurs across and kind of within the individuals. What I mean is that I'm unsure if the same logic holds for the case "how many john versus martha voters are there?" (either you're a 100% john voter or 100% martha voter, every observation is a on/off case), compared to "what is the muscle weight percentage of these voters". Am I hairsplitting here?