Common Use Cases for Preservation Metadata

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Common Use Cases for Preservation Metadata

• Deborah Woodyard-Robinson
• Digital Preservation Consultant
• deb_at_woodyard-robinson.com
• Long-term Repositories Taking the Shock out of
  the Future,
• APSR, NLA, Canberra, Australia , 31 August 2006

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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
Functions as use cases
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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

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Digital information

• Step back further to understand the source of
  these functions
• Digital information exists on 3 levels

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Intellectual (e.g. its a photo of Deb dancing)
Conceptual (e.g. its a file called IMGP0132.jpg)
0101010111 1001010010 0010011001
Physical (e.g. its a CD-ROM)
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• 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.

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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)

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Intellectual Preservation Description Information
Conceptual Content Information including
Representation Information
0101010111 1001010010 0010011001
Physical Packaging Information
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Understandability Authenticity Identity
Intellectual Preservation Description Information
Conceptual Content Information including
Representation Information
Renderability
Physical Packaging Information
Viability
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Maintain Renderability
Monitor technology
Customer
Staff
Design preservation actions
Supply renderable version
Repository System
Perform preservation actions
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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

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Maintain Renderability
Monitor technology
Customer
Staff
Design preservation actions
Supporting metadata required for these
functions Object Identifier Preservation
level Format Inhibitors Environment Relationships-
structural
Supply renderable version
Repository System
Perform preservation actions
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Maintain Viability
Monitor storage media
Staff
Refresh media
Replicate on backup media
Content Location Storage Medium
Repository System
Replace media
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Maintain Understandablility
Record history provenance
Customer
Staff
Maintain Context
Creation details Original file name Relationships
context Rights Events Agents
Repository System
Understandan object
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Maintain Authenticity
Check Fixity
Customer
Apply fixity check
Read signature
Fixity / check-sum details Digital signature
details
Repository System
Apply signature
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Maintain Identity
Apply unique identifier
Customer
Repository System
Resolve unique identifier
Object Identifier
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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 level
• User community gt Understandability details
• Authenticity

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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

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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

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Viability

• Government record archives
• Private sector library

• Requires
• Content Location
• Storage Medium

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Renderability

• Government record archives
• Private sector library

• Requires
• Object Identifier
• Format details
• Inhibitors
• Environment details
• Relationships- structural

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Understandability

• Government record archives
• Private sector library

• Requires
• Creation details
• Original file name
• Relationships context
• Rights
• Events
• Agents

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Understandability

• Government record archives
• Private sector library

• Requires
• Creation details
• Original file name
• Relationships context
• Rights
• Events
• Agents

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Authenticity

• Government record archives
• Private sector library

• Requires
• Fixity / check-sum details
• Digital signature details

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Authenticity

• Government record archives
• Private sector library

• Requires
• Fixity / check-sum details
• Digital signature details

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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

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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

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Summary

• Problem gt solution gt functions
• Functions gt use cases
• Use cases gt metadata (Reality check 1)
• However, do rememberThe information you need to
  know may not need to be explicitly recorded in
  object metadata to be functional (Reality check 2)