The European Social Survey (ESS) is a pan-European research infrastructure providing freely accessible data for academics, policymakers, civil society and the wider public. It was awarded European Research Infrastructure Consortium (ERIC) status in 2013.

The work of the ESS ERIC includes organising a survey every two years measuring social attitudes and behaviour; utilising and developing the highest standards in cross-national research; providing direct and virtual training programmes; and supporting free access to its growing data and documentation archive (www.europeansocialsurvey.org).

The ESS has been mapping attitudes and behavioural changes in Europe’s social, political and moral climate for over 15 years. Launched in 2001, the first round of surveys was conducted in 2002 and gathered results from 22 countries. Since its inception, 36 countries have taken part in the ESS.

By adopting rigorous approaches to probability sampling, question-testing, event-recording, translation and response rate enhancement, the ESS has become THE authoritative source of information about changing social values in Europe.

This general social survey measures attitudes on a wide range of subjects. The ESS was primarily designed as a time series to monitor changing attitudes and values across Europe. The questionnaire therefore consists of a main core section that includes a number of questions that have been answered every two years since 2002. Each question has a unique identifier to enable people to easily compare data over time.

The development of this ‘core’ part of the ESS questionnaire followed recommendations made by academic experts who were consulted by the Core Scientific Team during the early planning stages of the ESS.

Additionally, in each round of the ESS, multi-national teams of researchers based in ESS countries are selected to contribute to design part of the questionnaire. Two ‘rotating’ modules are selected following a Call for Proposals placed in the Official Journal of the European Union (OJEU).

As a result, the ESS always includes questions measuring attitudes towards the media, health and wellbeing, trust in institutions and governments, education and occupation, social capital and social trust, household circumstances, citizen involvement and democracy, social exclusion, political values and engagement, socio-demographics, immigration and crime.

The ESS has asked questions designed in collaboration with external academics on citizen involvement, health and care, economic morality, family, work and wellbeing, timing of life, personal and social wellbeing, welfare attitudes, ageism, trust in the police and courts, democracy, immigration, social inequalities in health and attitudes to climate change and energy security. Some of these topics have been repeated at a later stage.

By measuring the results over time, the data reveals intriguing contrasts and similarities between European countries. This rigorous comparative data collection is then used by the academic community, their research often facilitating pan-European and member state political, social and economic debate. This allows scholars, policymakers, think tanks and other interested parties to measure and interpret European people’s views cross-nationally and over time.

Seven rounds of survey data have now been compiled, fieldwork for the eighth began in September 2016 and the ninth round will be running officially from 1 June 2017 to 31 May 2019.

The ESS annotates its source questionnaire to guide translators in using national instruments so that the survey has the same meaning in every language. The questionnaire is translated into any language spoken as a first language by more than five per cent of each country’s population.

In line with the central Specification for Participating countries made available for each round, each National Coordinating Team identifies a suitable sampling frame and produces a sample design to be implemented in their country.

The ESS provides comprehensive materials for interviewer training and briefing sessions. It is vital that the interviewing is as consistent as possible across all European countries taking into account necessary national adaptation. Briefing sessions explain the ESS project: the questionnaire and rules. All interviewers must be personally briefed upon being assigned to undertake ESS fieldwork.

The survey fieldwork is gathered over a minimum of one month within a designated maximum period of four months, and all countries aim to interview at least 1,500 respondents, though this number is reduced for countries with smaller populations. Once the fieldwork is completed, National Coordinating Teams deposit their data in the ESS data archive. This data is available to everyone for free.