How does a company calculate or statistically back up brand awareness?

By conducting surveys of representative samples of local populations.

It’s probably overstated in the sense that some populations may not be readily surveyed.

They might have included random/specific samples from other parts of world in addition to US. And, from those samples, they may have drawn above statistical inferences.

GA @kevbo!

Or, frankly, they could have made the figure up, or based it on wild guesses and extrapolations on data that does not work for the purpose at all, or that has been knowingly manipulated. Not saying they did, in this specific case, but a lot of the time when someone quotes a percentage figure in publicity, it has nothing to do with actual data.

People call you at dinner time or when you are taking a nap and say they just have a few questions to ask. Then the ask you the same group of question in at least 3 different wasy or in some kind of ridiculous range (Answer from extremely well to not at all) and keep you on the phone for 20 minutes. The data received from these surveys are almost always skewed because the only information they get is from shut-ins or people who are terminally kind. The rest of us hang up.

One way might be the return cards packed inside the product, and another might be the information collected by websites and google/yahoo that is sold to the companies.