DDI-Codebook (DDI-C)
Current Version: 2.6 (2026-04-15)
Current Field Level Documentation
XML Schema namespace (use in xsi:schemaLocation declaration if not using a local copy of the schema set): https://ddialliance.org/Specification/DDI-Codebook/2.6/XMLSchema/codebook.xsd
Supports Activities
- Descriptive documentation of the content, meaning, provenance, and access for a single data set
- Archival preservation of descriptive content
- Input basis for more complex descriptions
- 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
- Supports the use of external controlled vocabularies for improved searching and comparability between datasets
- Improved description of processing and analysis activities through incorporation of support for SDTL
Structured, descriptive documentation of the content, meaning, provenance, and access for a single data set. Originally developed as an XML DTD, DDI-Codebook retains the hierarchical structure of a DTD in describing the contents of a descriptive codebook for a data set including: identification, authorship, ownership, purpose, background methodologies, source information, provenance, quality control, access, physical file structures, variables/variable groupings, and related materials. Extensive information is found within the variable description covering the data source, derivation activity, representation, data typing, variable role, and restrictions.
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Change Log v2.5
- Metadata Examples
- A listing of available examples of DDI Codebook instances (filter by version is available)
- DDI Profiles
- Profiles used by organizations or applications
- Tools used to create, display, and access DDI instances (filtered by product)
- Training Materials
- DDI Glossary
- Development of DDI-Codebook is managed by the DDI Alliance Technical Committee (TC). The work of the TC can be found at Technical Committee - DDI - Confluence (atlassian.net) (external site). Issues related to the general development of DDI Codebook are managed at DDI: Codebook - Issues - JIRA (atlassian.net) (external site). File specific model issues in Development Repository (GitHub site).
DDI-Codebook 2.6 XML Schema is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License.
This is a human-readable summary of (and not a substitute for) the license (https://creativecommons.org/licenses/by/4.0/legalcode)
You are free to:
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Adapt — remix, transform, and build upon the material for any purpose, even commercially.
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You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
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You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation.
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For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.