DDI Codebook

Israel Social Science Data Center (ISDC)

The ISDC Data Catalog contains information on over 600 datasets covering an extensive range of key economic and social quantitative data, spanning several disciplines and themes. The bulk of the datasets described in this catalog are micro-level. Each dataset within the collection is described by bibliographic details, methodological information, abstract, geographical coverage and temporal coverage. Links to associated metadata include references to publications, subject keywords, extended metadata sources and links to related datasets, clustered in "Data Series".

Institute for the Study of Labor -- IZA, International Data Service Center (IDSC)

The Institute for the Study of Labor (IZA) in Bonn, Germany, is a private, independent research institute focusing on the economic analysis of national and international labor markets. The institute conducts extensive research in all relevant areas of labor economics and advises policymakers on current labor market issues. Financed by Deutsche Post World Net, IZA cooperates closely with the University of Bonn and other academic institutions.

ICPSR Social Science Variables Database (SSVD)

The Social Science Variables Database, created with funding from the National Science Foundation as part of ICPSR's Infrastructure in the Social Sciences award (SES-9977984), is a database of over 4 million variables from ICPSR data. The SSVD enables the user to search for variables, compare variables across studies, and view the question text for select variables.

ICPSR Data Catalog

ICPSR provides all of its metadata records in DDI format. About 75 percent of the holdings also have DDI-compliant variable-level information.

General Social Survey

The General Social Survey (GSS) is one of NORC's flagship surveys and its longest running project. Begun in 1972, the GSS and has been monitoring social change and the growing complexity of American society.

European Social Survey (ESS)

The European Social Survey (ESS) is an academically driven cross-national survey that has been conducted every two years across Europe since 2001. The survey measures the attitudes, beliefs and behaviour patterns of diverse populations in more than thirty nations.ESS data are provided in the Nesstar online analysis system.

The Dataverse Network

The Dataverse is an open source web application to share, preserve, cite, explore and analyze research data. It facilitates making data available to others, and allows you to replicate others work. Researchers, data authors, publishers, data distributors, and affiliated institutions all receive appropriate credit.

A Dataverse repository hosts multiple dataverses. Each dataverse contains datatset or other dataverses, and each dataset contains descriptive metadata and data files (including documentation and code that accompany the data).


CIVICACTIVE is a project pertaining to elections and referendums in Europe, and this site, which uses Nesstar, is part of the dissemination strategy of the CIVICACTIVE project. It provides an online database of aggregated election statistics from European Parliament elections: national parliamentary and presidential elections as well as EU-related referendums held in EU member countries starting in 1990.

Centers for Medicare/Medicaid Services (CMS) Denominator File Project

The purpose of this project, conducted by the Research Data Assistance Center at the University of Minnesota, was to compile, organize, and structure the documentation for the Medicare beneficiary demographic and enrollment data so the documentation is suitable for research and statistical use. To accomplish this goal, the project employed the DDI.