The modules 2003 (“National Identity”) and 2004 (“Citizenship”) of the International Social Survey Programme were conducted in the Netherlands as a stand-alone postal survey at the Free University Amsterdam [VUA] (Faculty of Social Sciences, Department of Social Research Methodology) by Harry B.G. Ganzeboom [principal investigator] and Elsbeth de Groot [fieldwork manager]. As of 2005, VUA has taken over the Dutch national membership for the Netherlands, formerly held by the Social and Cultural Planning Office [SCP] in The Hague, with Jos Becker as principal investigators. Funding for the 2004-2005 data collection was equally supplied by the SCP and the VUA.Note that this dataset is more elaborate than the Dutch part of the international ISSP file, archived at GESIS - Leibniz Institute for the Social Sciences, Cologne, Germany.