DDI-Lifecycle

Support for the DDI Lifecycle from planning through analysis. Organized around major areas of activity: Conceptual Content, Study Unit, Data Collection, Logical Records, Physical Records, Physical Instances (data store), Archiving, Groups, Resources, and Comparison. Introduces the idea of metadata reuse within and between studies, support for repeated surveys, creation and management of questionnaires, and management of metadata over time. Content may be used to populate question, variable, and concept repositories.

Lifecycle expands on the idea of Codebook in terms of content coverage, depth, metadata management over time, reusable metadata, and support for the planning, capture, processing, storage, discovery and dissemination of research data. Lifecycle is the most comprehensive of the DDI products covering conceptual and methodological objects, processing, quantitative and qualitative data objects, and data management. Lifecycle is appropriate for longitudinal, linked, and other complex datasets.

Supports Activities:

  • Descriptive documentation of the content, meaning, provenance, and access for a single data set or series

  • Archival preservation of descriptive and production content

  • Metadata driven statistical systems

  • Input content for discovery and exchange of data at the study, data file, variable, and question level

  • Input content for a structured human-readable codebook for the data set as a whole

  • Populate variable and question banks to explore available data and question structures for reuse in new surveys

  • Metadata reuse for quality control and consistency

  • Reuse of metadata within and between studies

  • Defining intended processes for data capture, processing, preservation, and access

  • Management of single or multi-model data capture including generation of data capture forms and instrument content

Version 3.3 [current]

Publication date: 2020-04-15

Additions in version 3.3: This version also supports improvements in Classification management (based on GSIM / Neuchatel), non-survey data collection (Measurements), sampling, weighting, questionnaire Design and support for DDI as a Property Graph.

Version 3.2

Publication date: 2014-03-12 Updated: 2024-05-15

Implementation Guide

NOTICE 2014-05-15: The DDI 3.2 schema package was reissued on 2014-05-15 to correct an error in the HTML version of the Field Level Documentation which resulted in a small number of broken links. No change has been made to the contents of the schemas themselves.

This version of the DDI Lifecycle specification builds on DDI Lifecycle 3.1, correcting documented bugs and refining some aspects of the specification.

Version 3.1

Publication date: 2009-10-15

DDI Lifecycle 3.1 reflects the correction of bugs identified by implementers using DDI 3.0, and the resolution of the final URN structure to ensure persistent URNs for all identified elements. Note that DDI Lifecycle 3.1 is not backward compatible with DDI Lifecycle 3.0. A change file in the download package identifies all changes, including which changes were backward compatible and the steps to take to move DDI Lifecycle 3.0 instances to DDI Lifecycle 3.1.

Version 3.0

Publication date: 2008-04-28

DDI Lifecycle 3.0, published in April 28, 2008, represented a major advancement for DDI by fully incorporating XML Schemas and moving to a data life cycle approach. Element content for DDI 3.0 was developed by several Working Groups with the technical specification itself created by the Technical Implementation Committee (TIC).

The intent of DDI Lifecycle was to support the management, preservation, and dissemination of complex social science data files. The ability to manage and reuse content improves the ability to capture metadata at its point of origin and then track its use and change over time.