DDI Cross Domain Integration (DDI-CDI) Review

Intent of DDI-CDI

DDI - Cross Domain Integration (DDI-CDI) is a specification aimed at helping implementers integrate data across domain and institutional boundaries. Modern research increasingly involves large amounts of data, much of which comes from non-traditional sources (sensors, big data, social media, etc.) and often from other domains. DDI-CDI focuses on a uniform approach to describing a range of needed data formats (traditional wide/rectangular data, long [event] data, multi-dimensional data, and NoSQL/key-value data) which allows them to be connected and understood to support transformation and processing for integrated use.

Further, the aspects of data provenance related to data processing are covered, to document the ways in which data are sourced - this is a key aspect of data description when working with data from unfamiliar domains, which may be the product of an unfamiliar production lifecycle. DDI-CDI is aligned with other DDI specifications (DDI-C, DDI-L) to support integration of external data in systems which use DDI. It is explicitly designed to work with many popular generic technology standards such as PROV-O, BPMN, DCAT, SDMX, DataCube, SSN/SOSA and Schema.org to allow for easy integration into systems which support them.

DDI-CDI offers an extension to the suite of DDI work products which will help those in the SBE domains and outside of them integrate the expanding range of data required by today's research.

Download and Overview of Content for Review


All materials for the initial round of public review for the DDI Cross Domain Integration (DDI – CDI) specification can be found in this download.

CLICK HERE to download all content for review.
It is recommended to unzip the downloaded file into a folder with a short path name (like "c:\ddi") otherwise some Windows systems might complain about too long path names.

Access all individual content documents from an index page.

It is recommended that access to the field level documentation for the Model be through the link from the index page. It requires that Javascript be supported by the browser used to view it. This can cause problems for local files with some browsers’ security settings.

Overview (this document)

Credits and Licensing document

Open Issues and Future Steps document

Specification Documents folder:

This folder contains four documents, describing the DDI – Cross Domain Integration specification at a high level. These include an introductory document, a document giving a more detailed description of the model (Foundational Metadata, Data Description, and Process), a document outlining the architecture and approaches to modelling and alignment with other standards/technical specifications, and a set of documentation giving more complex examples and use cases.
In the Supporting Documents sub-folder are documents covering the subset of UML used in the DDI – CDI model.

The following primary documents are also available through the following links:

Model folder:

This folder contains two versions of the model in Canonical XMI (the XML interchange format for UML models), one using unique association names and one as documented in the specification documents (some UML tools demand this uniqueness, others do not). There is also a copy of the Sparx Enterprise Architect file used by the development team, for those reviewers who use this tool. All diagrams in the detailed model are included in the EA file.

In the Field-Level Documentation sub-folder is the HTML field-level documentation for every construct in the model. To view online version click here.

In the Supporting Documents sub-folder is a file containing all of the diagrams used on the model, which may be more suitable for reading (“zooming in”) and display than those found in-line in other documents.

Syntax Representation folder:

There is only one syntax representation included in the public review package: Extensible Markup Language (XML). This can be found on the XML Syntax Representation sub-folder.

This folder contains the XML Schema definition file for the XML representation of DDI – CDI, as well as the required “xml.xsd” file. Release notes are included.

In the Examples sub-folder are the three XML examples created in support of the examples and use cases document. In the HTML XML Schema Documentation sub-folder is a zipped archive containing the field-level documentation for the XML Schema. To view online version click here.

Examples folder:

This folder contains other examples mentioned in the examples and use cases document.

File a Comment

Your feedback to DDI-CDI is appreciated!

CLICK HERE to view a list of issues filed against this specification or to file and issue.