As in the article, I think it depends to some extent on what question you're asking. "What is the population of the US?" is almost definitely intended to includ

As in the article, I think it depends to some extent on what question you're asking. "What is the population of the US?" is almost definitely intended to include Alaska and Hawaii, but if someone asks "what is the geographic center of the US," they probably intend for the answer to be something in South Dakota, not the point off the coast of British Columbia that you get if you include Alaska and Hawaii, or the point out in the middle of the Pacific if you include Guam, etc.