This course is an introduction to the design and analysis of social and political surveys. It is intended both for students who plan to design and collect their own surveys, and for those who need to understand and use data from existing large-scale surveys. On today, surveys data play a very important role in modern democracies, the accuracy of surveys (for instance elections surveys) is sometimes contested. Is this very important for social scientists, journalists, policy experts, to know more about the “black box” of the making of a good survey, its power but also its limits. The topics covered in the course aim at offering a complete panorama of the most important and up-to-date methodological issues of surveys, in a world where online interview tends to dominate the survey market.