This paper briefly introduces the social and cultural demography of minorities. Summarizing the papers presented in this special issue, we focalize on the methodological challenge: sampling strategies, data construction, analytical tools, and their implications in terms of results. It is essential to always explicitly address the issue of the interrelations between the definition of a subpopulation and the demographic peculiarity of this group. We conclude on the necessity to explore more systematically the question of multiple affiliations.