With the Amsterdam Treaty and the increasing competence of the European Union in the field of migration, integration, anti-discrimination and asylum, the need for comparative data in the this area has been increasingly recognized. Social scientists, on the other hand, have a much broader agenda for comparative research, that goes beyond the immediate needs of policy makers and requires much more sophisticated data as well as knowledge about datasets that might be used for comparative research purposes. The objective of the project is to promote comparative quantitative research in the field of migration and integration. It will do so in three respects: First, an online accessible database will be established, based on a database developed in a pilot project and containing essential technical information on statistical datasets in 27 European countries as well as the variables included in these dataset. Second national data collection systems will be systematically described in the form of brief country report. which will provide essential contextual information necessary to understand statistical data in the area of migration and integration more generally. Third, and most important, thematic studies will explore the possibilities for, and the possible limitations on conducting research in a number of different thematic areas based on an evaluation of the datasets included in the database. Through the thematic studies, the online portal will also serve as a platform for the discussion of fundamental methodological problems in this field as well as a tool for dissemination of project result.