The PREMIS Editorial Committee is pleased to announce the availability
of *version
3.0 of the PREMIS Data Dictionary for Preservation Metadata**.*
This is a major new version with a revised data model, enhancing the
ability to express information about software and hardware environments and
intellectual entities.
The *PREMIS Data Dictionary for Preservation Metadata version 3.0* is
available from: http://www.loc.gov/standards/premis/v3/. It includes
extensive discussion of the revised data model and the expanded description
of environments in its Introduction and Special Topics sections.
To enable automated workflows, there are many PREMIS semantic units that
recommend that the value be taken from a controlled vocabulary. In previous
versions the Data Dictionary included suggested values; most of these were
included in LC’s Linked Data Service for Authorities and Vocabularies (
http://id.loc.gov/preservationdescriptions/). In this version, some
examples rather than suggested values are given, and the semantic unit
refers to the specific vocabulary in the id.loc.gov system. Additional
terms will be added to accommodate the new or revised semantic units in
version 3.0.
The PREMIS XML schema is undergoing revision and will be available in
the near future. When a draft is available it will be announced, and PREMIS
implementers are encouraged to experiment with it and provide feedback. In
addition, the PREMIS OWL ontology will be revised to reflect these changes.
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*Specific changes in this version include**:*
**Make Intellectual Entity another category of PREMIS Object*.
In versions 1 and 2 an Intellectual Entity was a separate entity and was
out of scope for description using PREMIS except for an identifier to link
to it from other PREMIS entities. This change will enable a repository to
represent an aggregate, such as a collection, FRBR work or expression,
fonds or series, in order to capture descriptive metadata, to associate
business requirements with it (such as significant characteristics, risk
definitions, guidelines for preservation actions, etc.), to support
structural and derivative relationships, to make rights statements, and to
establish relationships to preservation events. In addition it will allow
for the repository to capture versioning information and metadata update
events at the Intellectual Entity level for resources such as articles or
issues.
**Revise the data model so that software and hardware environments can
be described and preserved reusing the Object entity*. In order to preserve
Digital Objects, repositories need to have information about the elements
of the technical stack of software, hardware and other dependencies needed
to correctly interpret the representations, files and bitstreams. This is
particularly important for certain types of resources that are dependent on
combinations of hardware and software for their use, e.g. multimedia or web
sites. In previous PREMIS versions, environment descriptions were
associated with each individual Object; now they may 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 may link to
environment descriptions in external registries. Environments can be
represented as aggregates or as individual components (e.g. an executable
file, a stylesheet); therefore, relationships become crucial. 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 and are thus no longer out of scope for PREMIS
descriptions.
**preservationLevelType is added* as a new semantic unit 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”.
**agentVersion is added* to the Agent entity to express the version of
software Agents.
**compositionLevel is no longer restricted to an integer*, so that
*an *“*unknown”
value *may be used if the information is not available. An “*unknown” value
may also apply to formatName*, which is a mandatory semantic unit, for
unidentified formats.
Angela Dappert
PREMIS Editorial Committee
