The CESSDA Metadata Model contains metadata elements, their definitions and information on other requirements, such as repeatability. The Model is built from the viewpoint of quantitative (social science) data and is based on DDI Lifecycle 3.2 metadata standard.

The profiles specify the metadata requirements of the CESSDA Data Catalogue, based on the CESSDA Metadata Model and the DDI specifications.

A widely used, international standard for describing data from the social, behavioral, and economic sciences. Two versions of the standard are currently maintained in parallel:

  • DDI Codebook (or DDI version 2) is the simpler of the two, and intended for documenting simple survey data for exchange or archiving. Version 2.5 was released in January 2012.
  • DDI Lifecycle (or DDI version 3) is richer and may be used to document datasets at each stage of their lifecycle from conceptualization through to publication and reuse. It is modular and extensible. Version 3.2 was published in March 2014.

Both versions are XML-based and defined using XML Schemas. They were developed and are maintained by the DDI Alliance.