DDI-Codebook

DDI-Codebook Development History

DDI Codebook was the first version of the DDI to be published (Version 1 was released in 2000). DDI 2.0 was released in 2003, with Version 2.1 following two years later. Version 2.* added coverage of aggregate data and geography. The canonical expression of DDI 1.* and 2.* is a Document Type Definition (DTD), although XML Schema versions have been created.

A new version in the DDI Codebook line -- 2.5 -- is under review as of October 25, 2011. This version is an XML Schema. It incorporates new substantive elements requested by the community and is designed to make it easier to migrate documents to DDI Lifecycle for those interested in doing so.

DDI Codebook 2.5 is backward compatible with DDI 2.1. A change log in the download package identifies all changes. To comment on DDI 2.5, please send email to the Technical Implementation Committee.

DDI Codebook 2.5 (under review)

DDI Codebook 2.1