All CNEP surveys include a common core of questionnaire items dealing with the research themes that unify this project.  Items dealing with similar themes are grouped together in the Common Core Questionnaire and identified by alphabetic prefixes:  A includes short-term campaign issues (e.g., satisfaction with the performance of the incumbent government); B deals with attitudes toward democracy and democratic participation; C items consist of more durable political attitudes (such as Party Identification and Left-Right self-placement); D variables are comprised of items tapping into communication channels through which respondents receive information about politics (social media and the internet, newspapers, radio and television); E items deal with face-to-face contacts relevant to political communication; F includes secondary organizations as conduits of political information; the H category is more heterogeneous, including levels of political knowledge and engagement, especially voting behavior; I captures flows of information through partisan political channels; J includes various socio-political values that are of political relevance; K takes in a number of variables dealing with norms of democratic participation and the fairness of electoral processes; L contains a number of sociodemographic variables; and N deals with sub-national political identities and preferences regarding state structure.

Most surveys also include country-specific questionnaire items that are not part of the common core.  These are not included in the Merged file, but they are retained in the individual .Fin country files.