From the labour force survey Istat derives its official estimates of the number of employed persons and job-seekers, as well as information about the main labour supply aggregates, such as occupation, economic activity area, hours worked, contract types and duration and training. Since being introduced at the beginning of the 1950s, the survey has played a primary role in the statistical documentation and analysis of the employment situation in Italy and has proven to be an indispensable instrument of knowledge for public decision-makers, the media and citizens alike. Istat collects the information each year by interviewing a sample of over 250,000 households, representing 600,000 individuals who are resident in Italy, even if they are temporarily abroad. Households usually living abroad and permanent members of communities (religious institutes, military barracks, etc.) are not included. The survey has been updated over the years to take into account continual transformations in the labour market on the one hand, and the growing information requirements of users regarding the social and economic reality of our nation, on the other. The most recent change was undertaken at the beginning of 2004 in line with European Union regulations. The current sample survey is continuous insofar as information is collected during every week of the year and no longer during a single week per quarter. The results are still disseminated on a quarterly basis, except for provincial data which are disseminated annually. A significant feature of the survey is the establishment of new criteria for identifying employed and unemployed individuals,as well as a far-reaching reorganisation of the data collection and production process. To make new estimates comparable with estimates referring to previous years, Istat has reconstructed the time series since the fourth quarter of 1992.