In 2006 we were working together at a well-established institution with 40 years’ experience in conducting social and political surveys. Within our professional circle, the development of regular surveys of the general Spanish population posed few major challenges. At least one was conducted every month. However, an emerging development in Spanish society gradually began to demand more of our attention. This development created new challenges in survey design and, indeed, seemed to have the potential to change our professional lives.

Field reports from interviewers increasingly mentioned that dwellings where they tried to do interviews were occupied by non-Spanish people. When analysing the results it became evident that the most common surveys, covering only the Spanish population, increasingly reflected a lessthan- complete picture of society. In fact, they were missing an important new part of it. The public institutions for which we developed surveys were aware of the problem too. They began to ask us to broaden the target population to include foreign and immigrant populations and, in some cases, even to focus primarily on them. However, they did not realise the greater technical difficulties and much higher cost involved in doing this!

The need to address these new issues convinced us to organise an international workshop on the methodological challenges involved in surveys of immigrants and minorities. That workshop took place in Madrid in October 2008, with participants from nine European countries. The European Science Foundation sponsored the event and also provided funding for preparation of this manuscript. The participants in the workshop presented analyses of various methodological issues (sampling, fieldwork, etc.) faced in surveys of immigrants and foreigners (or of general population surveys that include them). This book contains papers based on those presented at the workshop. A few of the Madrid papers did not evolve into chapters, but we want to thank their authors, Michael Blohm, Giancarlo Blangiardo, Dirk Jacobs, Vincent Tiberj, Orkeny Artal and Henk Stronkhorst (as the ESF's representative) for their contributions to the discussion of the issues covered here. We also include here several new contributions from European contexts (Denmark and Switzerland) and North America (United States).

We thank the three IMISCOE anonymous reviewers who made excellent suggestions for improving the manuscript.