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Common Use Cases for Preservation Metadata. Deborah Woodyard-Robinson Digital Preservation Consultant [email protected] Long-term Repositories: Taking the Shock out of the Future , APSR, NLA, Canberra, Australia , 31 August 2006. Use of use cases. - PowerPoint PPT Presentation
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Common Use Cases for Preservation Metadata
Deborah Woodyard-RobinsonDigital Preservation Consultant
Long-term Repositories: Taking the Shock out of the Future,
APSR, NLA, Canberra, Australia , 31 August 2006
Use of use cases
Broad use cases : viewed from 2 angles
Metadata must support the functions in a system and the function (aim) of a system
A system(Repository)
as a use case
Functionsas use cases
PREMIS definitions
Preservation Metadata: Information a Preservation Repository uses to support the digital preservation process.
Digital Preservation Process: functions to maintain viability, renderability, understandability, authenticity & identity of digital material in a preservation context
Digital information
Step back further to understand the source of these functions
Digital information exists on 3 levels
PhysicalPhysical(e.g. it’s a CD-ROM)
ConceptualConceptual(e.g. it’s a file called
IMGP0132.jpg)
IntellectualIntellectual(e.g. it’s a photo of
Deb dancing)
0101010111
1001010010
0010011001
The OAIS recognises these levels and discusses functions to do this as well as the information required to support these functions, i.e. the metadata.
OAIS metadata
Packaging Information (i.e. how and where the bits are stored)
Content Information including Representation Information (i.e. how to locate the bits and interpret the bits into data)
Preservation Description Information including Reference Information Context Information Provenance Information Fixity Information
(i.e. how to identify the data and interpret the data into information)
PhysicalPhysicalPackaging Information
ConceptualConceptualContent Information including
Representation Information
IntellectualIntellectualPreservation Description
Information
0101010111
1001010010
0010011001
PhysicalPhysicalPackaging Information
ConceptualConceptualContent Information including
Representation Information
IntellectualIntellectualPreservation Description
Information
Viability
Renderability
UnderstandabilityAuthenticity
Identity
Maintain Renderability
RepositorySystem
Monitor technology
Customer
Design preservation
actionsSupply
renderable version
Perform preservation
actions
Staff
Use Case: Monitor technology
Description: Repository staff request or schedule a technology
report. The system creates a report on the file formats,
inhibitor types and technology required by repository contents.
An external survey is conducted by the system based on report results and level of preservation required.
The system registers endangered formats and technologies.
The System surveys possible solutions available from available registries.
The system creates a report of findings for repository staff
Maintain Renderability
RepositorySystem
Monitor technology
Customer
Design preservation
actionsSupply
renderable version
Perform preservation
actions
Supporting metadata required for these functions:Object IdentifierPreservation levelFormatInhibitorsEnvironmentRelationships- structural
Staff
Maintain Viability
Refresh media
Replicate on backup media
Replace mediaRepository
System
Monitor storage media
Content LocationStorage Medium
Staff
Maintain Understandablility
RepositorySystem
Customer
Record history & provenance
Maintain ContextCreation detailsOriginal file nameRelationships –
contextRightsEventsAgents
Staff
Understandan object
Maintain Authenticity
RepositorySystem
Customer
Check Fixity
Apply fixity check
Apply signature
Read signature
Fixity / check-sum details
Digital signature details
Maintain Identity
RepositorySystem
Customer
Apply unique identifier
Resolve unique identifier
Object Identifier
Application in a system
Different repositories have different needs and will use different functions and therefore different metadata
“Mandatory” if applicable Possible differences:
Handling objects at rep/file/bitstream levelUser community > Understandability detailsAuthenticity
Application scenarios/2 use cases
Government record archives large volumes of government records to be archived,
often under legislative obligation from electronic government initiatives
mandated to preserve records, but also implementing specific retention schedules
more influence over what the producers of records deposit
authenticity is usually a vital aspect
Application scenarios/2 use cases
Private sector library (e.g. Wellcome Trust) very specific collection remit main users of the collection are internal to the
organisation, therefore well defined user group and knowledge base
interest in content only, can easily discard ‘look and feel’ if not desired
can normalise files to one format to manage if desired
Viability
Government record archives
Private sector library
Requires: Content Location Storage Medium
Renderability
Government record archives
Private sector library
Requires: Object Identifier Format details Inhibitors Environment details Relationships-
structural
Understandability
Government record archives
Private sector library
Requires: Creation details Original file name Relationships –
context Rights Events Agents
Understandability
Government record archives
Private sector library
Requires: Creation details Original file name Relationships –
context Rights Events Agents
Authenticity
Government record archives
Private sector library
Requires: Fixity / check-sum
details
Digital signature details
Authenticity
Government record archives
Private sector library
Requires: Fixity / check-sum
details
Digital signature details
Implementation
PREMIS does not differentiate between what is required to be implicit or explicit
Mandatory means “need to know” rather than “must exist as a metadata element”
Record only if applicable. E.g. signature information required only if signatures are used
Example: The National Archives, UK
Identifier types are the same throughout the system so not explicit in metadata
Storage media and location handled by system Relationships between representation, file and bitstream
equivalents are implicit via the structure of data in the system. Format, inhibitor and environment information is/will be
kept via PRONOM Unique Identifiers and the PRONOM registry i.e. format name, environment details etc are known and explicitly
recorded but not held with the object Levels of preservation are recorded in policies and retention
schedules
Summary
Problem > solution > functions Functions > use cases Use cases > metadata (Reality check 1) However, do remember:
The information you need to know may not need to be explicitly recorded in object metadata to be functional (Reality check 2)
