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Convening on a quarterly basis, the Complex Digital Objects (CDO) Group started in March 2018 as an informal group of practitioners whose institutions are starting to collect—or interested in collecting—digital works created in uncommon or unstandardised formats that are also commonly composed of multiple components.

These works pose more and complex challenges to collect, preserve, and make accessible than works created in more common formats currently found within collections. This is for a few reasons:

  • Established processes cannot be easily or entirely applied.
  • Existing systems might not support requirements for catalogue records, ingest, preservation, data management, storage, or access.
  • File formats and metadata have not yet standardised.
  • Existing tools for capturing and providing access might not faithfully reflect more dynamic works.

The need for a forum to discuss collection management approaches, policies, and strategies that reflect new challenges practitioners are facing was clear. The cross-disciplinary nature of the CDO group, as well as the variety in expertise of its members, provides the opportunity for collecting institutions that have their own remits and approaches to share challenges and knowledge with one another whilst identifying areas of commonality to advance research and possible collaboration.

The expertise within the current group includes areas throughout collection management, including curation, digital preservation, and access, as well as specific knowledge of preservation and archiving of different types of objects. Different experts have come to specific meetings for feedback on ongoing projects or to contribute to specific subjects.


Defining the term complex digital object is challenging. These are works that comprise different components, digital and sometimes analogue as well, and will require knowledge and expertise from multiple disciplines to collect, preserve, and make accessible. For these reasons, the group decided that the term would remain broad and not impose any strict definition on the works that could be discussed.

  • Hardware and/or software dependencies
  • Born-digital with no analogue counterpart
  • Multiple components
  • Non-standard formats and metadata
  • New distribution models (e.g. x-as-a-service models)
  • Rapid obsolescence
  • Interactive (e.g. the viewer participates in the delivery in content)
  • Has more than one representation (e.g. exists as both a mobile app and a website, an onsite time-based media artwork that also has an online presence)
  • Other?

The group also recognises that creators will use whatever materials are available to them to create their work. For this reason, it is imagined that the above list of characteristics will evolve as the group discussed types of works.


The group is led by Caylin Smith (Cambridge University Libraries) and Patricia Falcao (Tate Time-Based Media Conservation) and includes members from the British Library, the V&A, the British Film Institute, Science Museum Group, Library of the University of Edinburgh, The National Archives, Digital Preservation Coalition, Imperial War Museum, and the Netherlands Institute for Sound and Vision.