PREMIS Data Dictionary for Preservation Metadata: Approved Changes for version 3.0 (from previous version 2.2):
The following changes have been approved by the PREMIS Editorial Committee and will be incorporated into version 3.0:
- Make Intellectual Entity another category of Object. In versions 1 and 2 Intellectual Entities were out of scope and semantic units to describe them were not included in the PREMIS Data Dictionary (except for an identifier to enable linking to a description). The PREMIS Editorial Committee had several requests to expand the Data Dictionary to describe intellectual entities and to allow for them to relate to other PREMIS entities. We developed use cases to support that. Intellectual Entities will have the same semantic units as Representations.
The main use cases are:
1. A repository may want to represent an aggregate, such as a collection, FRBR work, FRBR expression, fonds or series, in order to capture descriptive metadata, to associate business requirements with them (such as significant characteristics, risk definitions, guidelines for preservation actions, etc.), to support structural and derivative relationships with them, to enable relationships with rights and events entities. This can only partially be accommodated by container metadata systems (such as METS) and their associated descriptive or administrative metadata. The provenance aspects in this are part of the core preservation metadata.
2. The repository may want to capture versioning information and metadata update events at the Intellectual Entity level for Intellectual Entities such as articles or issues.
- Define preservationLevelType. A new semantic unit is being added to indicate the type of preservation functions expected to be applied to the object for the given Preservation level. An example might be where the preservation level type is “bit preservation level” and the repository elaborates by assigning “low”, “medium” or “high”, or where the preservation level type is “logical preservation level” and corresponding values might be “emulation” or “migration”.
- Add a new semantic unit to the Agent entity to express the version of software Agents: agentVersion (O, NR).
- Revise the data model so that Environments (i.e. hardware and software needed to use digital objects) can be described and preserved reusing the Object entity, rather than be included inside each individual Object. They can be described as Intellectual Entities and preserved as Representation, File or Bitstream Objects. Semantic units that are specific to Environment descriptions capture the function and designation of the Environment, and link to descriptions in external registries. Environments can be represented as aggregate environments or as individual components of an environment (e.g. an executable file, a stylesheet); therefore, relationships become important. A direct relationship between Agents and Objects will now be used to capture the Environment that acted as the Agent in an Event.
- Physical Objects can be described as representations and related to digital objects.
- A value of unknown will be added to compositionLevel and format if the information is not available.
- eventDetail was made extensibile and repeatable.