Sampling and Fieldwork

The Sampling

For each Eurobarometer new and independent samples are drawn, which is also true for all additional surveys with identical basic survey id name (e.g. 47.0, 47.1 and 47.2).  Since Autumn 1989 (Eurobarometer 32) the basic sampling design in all member states is a multi-stage, random (probability) one. The sampling is based on a random selection of sampling points after stratification by the distribution of the national, resident population in terms of metropolitan, urban and rural areas, i.e. proportional to the population size (for a total coverage of the country) und to the population density. These primary sampling units (PSU) are selected from each of the administrative regions in every country. Starting with Eurobarometer 32 NUTS (EUROSTAT Nomenclature of Territorial Units for Statistics with multiple level of codes [hierarchical list of NUTS regions] [maps of NUTS regions]) level 2 regions are applied for all member countries. 

In the second stage, a cluster of addresses is selected from each sampled PSU. Addresses are chosen systematically using standard random route procedures, beginning with an initial address selected at random. In some countries respondents are randomly selected from electoral registers, such as Great Britain (until Eurobarometer 35), Republic of Ireland and Luxembourg (until Eurobarometer 32). Sweden is using a random sample bought at the government census bureau. In each household, a respondent is selected by a random procedure, such as the first birthday method. Up to two recalls are made to obtain an interview with the selected respondent. No more than one interview is conducted in each household. In the case of special target groups (e.g. respondents aged 15 to 24) the sampling procedure can differ (e.g. quota sampling in Eurobarometer 34.2).

In previous Eurobarometer surveys, different sample methods were used which varied between countries. Until Eurobarometer 31A in Denmark, Luxembourg, and the Netherlands a random selection from the population or electoral lists (of individuals or households) was used, in Belgium, France, Italy, United Kingdom, and Ireland quota sampling established by sex, age and occupation on the basis of census data, in Greece, Spain and Portugal a random route procedure (combining the two precedent ones). Germany used quota sampling established by sex, age and occupation on the basis of census data until Eurobarometer 23 and random route starting with Eurobarometer 24.

The Interview

In all Eurobarometer member countries, fieldwork is conducted on the basis of detailed and uniform instructions. Equivalent basic bilingual (French and English) questionnaires are developed and translated into the other languages. Back-translation control is applied. Two (or more) language versions are used in Belgium, Luxembourg, Finland, starting with Eurobarometer 62 in Spain, in Estonia, Latvia, Malta and Turkey.

Interviews are conducted face-to-face in respondents' homes. By way of exception in Sweden interviews for survey 42 have been carried out by telephone. As far as the data capture is concerned, the use of CAPI (Computer Assisted Personal Interview) is for the first time documented for Eurobarometer 62 and for those countries were this technique was available.

The Institutes

Starting with autumn 2004 (Eurobarometer 62) the Standard Eurobarometer are run and coordinated by TNS Opinion & Social, a consortium formed by Taylor Nelson Sofres (TNS) and EOS Gallup Europe.

Between autumn 1998 (Eurobarometer 32) and spring 2004 the fieldwork was carried out by national institutes associated with INRA (International Research Associates) EUROPE - European Coordination Office in Brussels. INRA EUROPE was also responsible for the co-ordination and the production of the integrated data sets, starting with Eurobarometer 54 in co-operation with GfK in the new European Opinion Research Group EEIG. Until Eurobarometer 31A, the fieldwork was carried out by national organizations belonging to the European Omnibus Survey (EOS-GALLUP Europe). The surveys were then coordinated and integrated by 'Faits et Opinions' in Paris. 

All participating institutes are members of the "European Society for Opinion and Marketing Research" ESOMAR and comply with its standards.

© GESIS Meinhard Moschner 24.06.2008