In constructing DDI, special care was taken to review related standards as well as previous versions of DDI in order to provide clear mapping to the contents of outside standards or to incorporate content where appropriate. Over 25 standards were evaluated. This page described mapped relationships of DDI-Lifecycle to the following standards: DDI-Codebook; Dublin Core and MARC; GSIM (General Statistical Information Model); ISO/IEC 11179; ISO 19118 - Geography; SDMX; METS and PREMIS.
DDI is a very flexible and complex standard that may be used by various projects or organizations in “customized” ways that best answer specific needs. DDI profiles allow different agents or agencies to specify exactly how they use the DDI XML format, and thus help achieve seamless transfer and interoperability of DDI instances. A DDI profile describes the subset of valid DDI objects used by an agency for a specified purpose. This is documented in a DDI-XML format, which allows a set of declarations to be made, identifying specific fields in the DDI which are “Used” or “Not Used”. Various other qualifications can be made to restrict or default permitted values for specific elements, and human-readable documentation can be added.
The flexibility of DDI allows for many different applications and uses. This page provides a selection of markup examples demonstrating a variety of implementations.
There are many tools available to help you work with DDI, from authoring and editing to data transformations and conversions. They've been developed independently by a variety of organizations within the global DDI community: Commercial, governmental, and academic. This page lets you browse the full list of tools or filter the list according to your needs. There are three main categories of tools: Software, software components, and stylesheets.