- ICPSR - Inter-university Consortium for Political and Social Research
A data archive providing leadership and training in data access, curation, and methods of analysis for the social science research community; all metadata conforms to the DDI standard.
- The Institution for Social and Policy Studies (ISPS) Data Archive
Provides members of the scholarly community with access to files associated with scholarly studies for the purpose of replication, for all studies conducted by ISPS-affiliated researchers. ISPS metadata records conform to DDI requirements and include a minimal set of Dublin Core metadata elements.
- DDI - Data Documentation Initiative
An international standard for describing data from the social, behavioral, and economic sciences. Expressed in XML, the DDI metadata specification supports the entire research data life cycle.