The GESIS – Leibniz Institute for the Social Sciences is the largest German infrastructure institute for the social sciences. It is headquartered in Mannheim, with a location in Cologne. With basic research-based services and consulting covering all levels of the scientific process, GESIS supports researchers in the social sciences. As of 2017, the president of GESIS is Christof Wolf. GESIS is part of the Leibniz Association and receives federal and state funding. History Established in 1986 as German Social Science Infrastructure Services (), GESIS originally consisted of the three independent institutes: Social Science Information Centre (, IZ) in Bonn, Central Archive for Empirical Social Research (, ZA) in Cologne, and Centre for Survey Research and Methodology (, ZUMA) in Mannheim. In 2007, the three GESIS institutes merged into one. In November 2008, GESIS added "Leibniz Institute for the Social Sciences" to its name in order to emphasize its membership in the Leibniz Association. In November 2011, GESIS Bonn and Cologne were merged into one location in Cologne. Services The GESIS social science services available to support the work of researchers are aligned to the five phases of the research data cycle. Planning Studies & Collecting Data Survey Methods Consulting: How to Plan a Study – Consulting services to researchers throughout the course of a research project. Basic Knowledge – In the sense of Open Science get extensive information on all aspects of current social science research. Cognitive Pretesting – Optimising questions and survey instruments. Items & Scales – Researching and developing new items and scales for research projects. Sampling – Drawing of (telephone) samples and complex samples for research projects. Finding and accessing data ALLBUS (German General Social Survey / ) – GESIS collects up-to-date data on attitudes, behavior, and social structure from the German population. GLES (German Longitudinal Election Study) – Data from Germany's largest and most ambitious national election study for examining and analyzing the electorate is available free of charge. PIAAC (Programme for the International Assessment of Adult Competencies) – GESIS is an integrated partner in the OECD study examining adult competency levels simultaneously across 24 countries via its population survey of adult skills. ISSP (International Social Survey Programme) – The international collaboration conducts annual conjoint surveys on social science relevant topics across 48 countries. EVS (European Values Study) – The empirical longitudinal survey conducted in 47 countries is aimed at providing insight into changes in human