Are you talking of astrology? In that case, you can use randomly generated birthdays instead of asking people for their information. Anyhow, the elements of astrology are only one layer of what is. You see, astrology is much, much more than your sun sign as it includes all of the planets (even the dwarf planet, Pluto) in relation to the constellations and each other. Even a full natal chart does not imply all of the energy that one is related to, though I find they are still nice to work with (I don't mean to diminish Astrology, I only mean to say that they are a piece of what there is, rather than what is absolute).