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Data harmonization at all levels

There is a lot of valuable data collected on similar topics in same or different samples, in same or different study designs, or in different countries and over times. The combination of this data multiplies the potential gain of knowledge and leads to new, expanded perspectives. In order to achieve this, it is necessary to harmonize these data to make them comparable.

GESIS offers expertise and advice, tools and thematic harmonized data from different sources.


The GESIS software package offers a quick and easy way to harmonize variables and document the process.

Harmonization of substantive instruments

We support and advise you on the harmonization of content variables measured with different instruments.

HaSpaD - Harmonizing and synthesizing partnership histories

The HaSpaD project provides a tool that allows a customized harmonization and synthesis of partnership histories and further variables from different research data infrastructures.

ONBound - Old and new boundaries

By harmonization, cumulation and linking of survey, as well as macro data, the ONBound project has created a unique database for the social sciences that enables researchers to explore the interlinking of national and religious identities on multiple levels.


QuestionLink is a database of recoding scripts. For selected constructs the scripts harmonize all German instruments that were used by nine national or international survey programs.