DDI Recognized as an ISO Standard

I’m pleased to announce that the DDI Alliance suite of products is now codified by an ISO standard. On 6 March 2026, the International Organization for Standardization released ISO/PAS 25955 , formally recognizing the Data Documentation Initiative (DDI) within the ISO standards framework.

This milestone reflects many years of collaborative work by the international DDI community to support consistent documentation and interoperability of research and statistical data. The IASSIST community has played an especially important role in the development, implementation, and advancement of DDI metadata standards from their earliest stages.

The publication of ISO/PAS 25955 is a recognition of the strength of the DDI Alliance’s role as a globally trusted framework for documenting statistical and research data and supports its adoption by governments, statistical agencies, research infrastructures, and data repositories.

Why this matters

Publication as an ISO standard is an important step in strengthening the role of DDI in the global research data ecosystem.

ISO recognition:

• Increases international visibility and trust in DDI as a robust suite of products for describing research data
• Supports adoption by governments, national statistical agencies, archives, and research infrastructures that rely on ISO-recognized standards
• Strengthens interoperability between DDI standards and other international standards used across the data lifecycle
• Helps ensure the long-term sustainability and governance of the DDI suite as part of the broader standards landscape

For organizations managing, curating, and sharing data–especially in the social, behavioral, economic, and health sciences–this recognition reinforces DDI products as key tools for enabling better data documentation, discovery, reuse, and interoperability.

A community achievement

This publication would not have been possible without the dedication of many contributors.

We are deeply grateful to the members of ISO Technical Committee 46 / Subcommittee 4 (TC 46/SC 4) for their collaboration and support in bringing this work to publication.

Under the DDI Alliance, a temporary Working Group was established under the Scientific Board to plan this work, led by Dan Gillman. We extend special thanks to Dan and Arofan Gregory for creating the initial design of the ‘DDI Common Core ’ document. This served as the source for the ISO specification and defines the core elements of DDI–including the Variable Cascade, Unit Cascade, and Value Domains–within the Data Lifecycle.

Dan wrote the Common Core document, and this was used as the initial draft of the proposed ISO standard. This draft was submitted to ISO TC46/SC4. Dan also shepherded the draft following the ISO process to final publication.

We extend sincere thanks to the experts who devoted significant time to reviewing the specification and contributing thoughtful feedback throughout the ISO process. Their careful work helped ensure the quality and clarity of the final publication.

Finally, we thank the many members of the DDI community–technical contributors, reviewers, implementers, and organizational supporters–whose work over many years laid the foundation for this achievement.

Looking ahead

The publication of ISO/PAS 25955 marks an important milestone, but it is also part of an ongoing journey. The DDI Alliance will continue to work with partners across the international standards landscape to advance interoperability, support the evolving needs of data producers and stewards, and strengthen the infrastructure that enables high-quality, reusable research data.

For more information about ISO/PAS 25955 and what this recognition means in practice, especially for existing DDI implementations and DDI Alliance members, please visit the DDI Recognized as an ISO Standard (ISO/PAS 25955) page on DDI Alliance’s web site.

-Jared Lyle, Executive Director, DDI Alliance