We run a new survey module within SOEP-IS, the innovation panel within the German SOEP. For the first time, individuals in a large-scale population panel are systematically surveyed on their relative over-/underconfidence. Moreover, this module applies the same over-/underconfidence measures to several important life domains (like health, labor market, household incomes & assets etc.). This will allow for systematic comparisons of the incidence of over-/underconfidence across life domains - to explore, e.g., the question to which degree biased beliefs are systematic, i.e. similarly persistent as personality traits, or rather domain-specific.