The Eurobarometer is a exceptional instrument to follow public opinions and trends on a wide variety of issues relating to the EU. Its database since 1973 is one of the largest in the world. The Standard Eurobarometer survey, carried out each autumn and spring, is a cross-national longitudinal study, designed to compare and gauge trends within member states of the European Union. The Flash and Special Eurobarometer is carried out to investigate specific topics (Ex. the introduction of the Euro) and provides faster results.