# Data Documentation Initiative (DDI) Lifecycle

DDI Lifecycle is an international standard for describing the data produced by
surveys and other observational methods in the social, behavioral, economic,
and health sciences. DDI Lifecycle is a standard that can document and manage
different stages in the research data lifecycle, such as conceptualization,
collection, processing, distribution, discovery, and archiving.

This is DDI Lifecycle version 3.3, as approved by the DDI Alliance Scientific
Committee on 2020-04-15.

## Release Package

The DDI Lifecycle release package includes the following:

- XML schema
- XML schema documentation

Additional model documentation is available at
https://ddialliance.github.io/ddimodel-web/DDI-L-3.3/

## Acknowledgements

The development of DDI Lifecycle 3 draws on earlier DDI versions and work of
the committees and individuals who developed them as well as the collective
ideas, needs, and work of the Expert Committee of the DDI Alliance. Major
contributions to the development and structuring of DDI Lifecycle 3 were made
by the following individuals:

### Technical Committee (TC)

#### Current Leadership

- Wendy Thomas, Minnesota Population Center, Chair [2006-], Vice Chair [2004-2005]
- Jon Johnson, CLOSER, UCL Institute of Education, Vice Chair [2016-]
    
#### Current Members and Invited Experts
    
- Johan Fihn, Swedish National Data Service
- Daniel Gillman, Bureau of Labor Statistics
- Jay Greenfield, BAH
- Oliver Hopt, GESIS - Leibniz Institute for the Social Sciences
- Larry Hoyle, University of Kansas
- Jeremy Iverson, Colectica
- Olof Olsson, Swedish National Data Service
- Flavio Rizzolo, Statistics Canada
- Dan Smith, Colectica

#### Past Members and Invited Experts

- Cavan Capps, Invited expert 
- Mark Diggory, Harvard-MIT Data Center
- Guillaume Duffes, INSEE
- J Gager, Technical expert
- Arofan Gregory, Lead technical expert
- Pascal Heus, World Bank, Development Data Group (DECDG)
- I-Lin Kuo, Invited expert
- Ken Miller, UK Data Archive
- Chris Nelson, Technical expert
- Jostein Ryssevik, Open Data Foundation, Chair [2004-2005], Vice Chair [2006]
- Oliver Watteler, GESIS - Leibniz Institute for the Social Sciences
- Joachim Wackerow, GESIS - Leibniz Institute for the Social Sciences, Vice Chair [2007-2016]


### Substantive Working Group Members

- Iris Alfredsson, Swedish National Data Service (SND)
- Atle Alvheim, Norwegian Social Science Data Service (NSD)
- Titto Assina, UK Data Archive
- Phil Bardsley, University of North Carolina
- Sandra Cannon, Invited expert
- Gina-Qian Cheung, Institute for Social Research, University of Michigan
- Karl Dinkelmann, Institute for Social Research, University of Michigan
- Pat Doyle, U.S. Census Bureau
- Ilona Einowski, University of California, Berkeley - UCDATA
- Janet Eisenhower-Smith, University of Wisconsin
- Fred Gey, University of California, Berkeley - UCDATA
- Peter Granda, ICPSR
- Ann Green, Invited expert
- Lon Hofmann, Invited expert
- Sanda Ionescu, ICPSR
- Jeremy Iverson, Invited expert
- Reto Hadorn, Swiss Data Archive for the Social Sciences (SIDOS)
- Taina Jaaskelainen, Finnish Data Archive
- Peter Joftis, ICPSR
- Chryssa Kappi, Invited expert
- Mari Kleemola, Finnish Social Science Data Archive
- Hans Joergen Marker, Danish Data Archive
- Mark G. Maynard, Roper Center, University of Connecticut
- Katherine McNeill-Harman, MIT
- Pam Miller, UK Data Archive
- Meinhard Moschner, GESIS - Leibniz Institute for the Social Sciences
- Ron Nakao, Stanford University
- Tom Piazza, University of California, Berkeley - Computer-Assisted Survey Methods Program
- Pilar Rey del Castillo, Centro De Investigaciones Sociologicas (CIS), Spain
- Ed Ross, Invited expert
- Dan Smith, Invited expert
- Ed van Duizen, University of North Carolina
- Mary Vardigan, ICPSR


## DDI Alliance Members

We would like to thank the following member organizations which have supported
the DDI Alliance in their development of DDI Lifecycle 3.0 through 3.3:

- Australian Bureau of Statistics (ABS)
- Australian Data Archive (ADA)
- University of Alberta, Canada
- University of California, Berkeley -- Computer-Assisted Survey Methods Program and UCDATA, USA
- University of California, California Digital Library, USA
- University of California, San Diego, USA
- Centre for Longitudinal Studies, Institute of Education, University of London (Associate Member)
- Centro De Investigaciones Sociologicas (CIS), Spain
- Colectica (Associate Member)
- CEPS/INSTEAD, Luxembourg
- Cornell University (CISER)
- Danish Data Archive
- Data Archiving and Networked Services (DANS), The Netherlands
- Emory University, USA
- Eurostat
- Finnish Social Science Data Archive
- Food and Agriculture Organization (FAO)
- German Institute for International Educational Research (DIPF)
- German Socio-Economic Panel Study (SOEP)
- GESIS - Leibniz Institute for the Social Sciences
- University of Guelph, Canada
- Harvard University, USA
- Institute for Social and Economic Research (ISER)
- Institute for the Study of Labor (IZA), Germany
- International Association of Social Science Information Service and Technology (IASSIST)
- International Federation of Data Organizations (IFDO)
- Inter-university Consortium for Political and Social Research (ICPSR), USA
- Massachusetts Institute of Technology (MIT), USA
- University of Minnesota, Minnesota Population Center (MPC), USA
- National Opinion Research Center (NORC), USA
- Nesstar LTD., UK
- University of North Carolina, USA
- Norwegian Social Science Data Service (NSD)
- Open Data Foundation, USA (Associate Member)
- Pennsylvania State University, Social Science Research Institute, USA
- Princeton University, USA
- Research Data Centre of the German Federal Employment Agency, Institute for Employment Research (IAB)
- Roper Center, USA
- SPSS Inc., USA
- Stanford University, USA
- Statistics New Zealand
- University of Surrey, UK
- Survey Research Operations, University of Michigan
- Swedish National Data Service (SND)
- Swiss Foundation for Research in Social Sciences (FORS)
- Swiss Data Archive for the Social Sciences (SIDOS)
- University of Toronto Libraries
- University of Toronto Scholars Portal
- United Kingdom Data Archive
- United States Bureau of Labor Statistics (Associate Member)
- United States Census Bureau
- University of Washington, Center for Studies in Demography & Ecology (CSDE)
- Washington State University, USA
- University of Wisconsin, USA
- World Bank, Development Data Group (DECDG)
- Yale University, USA

## License

DDI Lifecycle 3.3 XML Schema is released under the terms of the Creative
Commons International:

http://creativecommons.org/licenses/by/4.0/