Digital Preservation Policy

Purpose

This policy statement indicates the directions the National Library of Australia intends to take in preserving its own digital collections, and in collaborating with others to enable the preservation of other digital information resources likely to be of value to NLA users.

The objectives of the Library’s digital preservation activities

The National Library’s preservation role is guided by its key objective to preserve and maintain all Australian and significant non-Australian library materials to ensure they are available for current and future use. This objective applies to both digital and non-digital information resources, although the Library recognises that it will use different methods and draw on different skills, procedures and partnerships, for managing digital and non-digital collections.

The National Library also seeks to help others preserve the Australian information resources for which they accept responsibility.

The nature of the Library’s digital collections

The National Library began acquiring digital information resources of enduring value in the mid-1980s or earlier. By mid-2001 the digital information resources for which the Library accepts some level of preservation responsibility included:

  • Australian online resources originally published on the Internet and selected for inclusion in the Library’s PANDORA archive
  • Australian digital publications originally published on physical carriers such as diskettes and CD-ROMs
  • Digital audio collections created as part of the Library’s Oral History collections
  • Preservation master digital copies of analogue material from the Library’s collections (and in some cases, from the collections of other institutions) resulting from digitisation programs
  • Computer files on physical carriers such as diskettes forming part of various Manuscript collections
  • Original digital images forming part of various Pictorial collections
  • Digital mapping products chosen for long-term retention by the Maps Collection
  • Computer files containing transcripts of the Library’s Oral History collections
  • The Library’s corporate records in digital form
  • Components of the Library’s website chosen for ongoing retention
  • Digital materials from regional partners where the Library accepts a preservation role
  • Metadata records of information resources.

Over time, this list of resource types can be expected to change in response to new business needs and opportunities such as domain-wide web harvesting, archiving of email discussion lists, and new forms of electronic communication.

The Library maintains various other policy documents and guidelines relevant to the way digital resources are created, selected, acquired, described and accessed, which can be found at http://www.nla.gov.au/policy/.

The challenges of keeping digital information resources accessible

The Library defines digital preservation as the processes involved in maintaining, and if necessary, recovering accessibility to digital information resources.

Ongoing accessibility of digital resources is threatened by many challenges. The challenges include:

  • The volume and growth in the amount of material to be maintained
  • Widespread use of relatively unstable media
  • Rapid changes in the availability of hardware, software and other technology required for access
  • The diverse and frequently changing range of file formats and standards
  • Uncertainty about the significant properties that must be maintained for different digital resources
  • The recurrent, critical and demanding nature of the threats to accessibility
  • Uncertainty about strategies and techniques for addressing the threats
  • The high costs of taking action
  • Administrative complexities in ensuring timely and cost-effective action is taken over very long periods of time
  • New models of "ownership" that impose property and other rights-based constraints
  • The as-yet ambiguous intentions and capabilities of a range of agents with a potential impact on accessibility.

Broad directions for the Library’s digital collections

Scope

The Library intends to preserve all the digital materials covered by this policy. However, it is likely that the Library will be need to allocate priorities for action, based on the relative significance of particular materials and the technical complexity of preserving access to them.

Models

The Library believes its digital archiving and preservation objectives will be best achieved by developing practices that comply with an adequate, coherent and widely understood framework for reliable, accountable and manageable digital archives.

The Library will use the broad understandings and concepts embodied in the Open Archival Information Systems (OAIS) Reference Model, when released as an agreed ISO Standard, as a conceptual check for its own archive construction and management. In developing systems and infrastructure to manage its digital collections, the Library will operate within the principles of reliable digital repositories as defined by relevant international standards and best practices.

The Library also recognises the value of practical experiments in developing useful new approaches. The Library will continue to develop process models addressing its particular business needs, clearly identifying and articulating points at which its practice does not comply with the OAIS Reference Model, and why.

Preserving accessibility

A key concept of the OAIS model is that of the “archival information package”, consisting of the digital object itself and all the information required to understand, present, and manage it.

In preserving the accessibility of digital resources, the Library will attend to three aspects of accessibility:

  • Maintaining the archival information package: the byte-stream which constitutes the digital object and the information needed to present it as a meaningful reproduction of the originally presented digital object;
  • Maintaining means of accessing an acceptable presentation of the digital object; and
  • Maintaining the ability to locate the digital object reliably.

Implementation - NLA digital collections

In implementing this policy with regard to its own collections, the Library will:

  • Monitor the preservation implications of any systems designed or put in place to manage its digital collections.
  • Apply priorities for preservation in an accountable manner in accord with publicly available guidelines.
  • Store and manage digital resources in ways that secure the integrity of the byte-stream, including appropriate automated checking, archiving and back-up regimes with high levels of redundancy and security, and with best practice disaster preparedness and recovery procedures.
  • Document its collections, including file formats, their software and hardware dependencies, and any features needing to be accommodated.
  • Define the significant properties (such as formatting/ “look and feel”, functionality, and information content) that need to be preserved for particular classes of resources.
  • Record preservation metadata that facilitate effective and efficient management, and enable the significant properties defined for specific resources to be re-presented.
  • Understand and document the threats to which the accessibility of its collections will be exposed.
  • Develop and monitor indicators of threats, aiming to understand when preservation action is needed with sufficient lead time to allow effective, manageable action to be taken.
  • Declare its preservation intentions responsibly, realistically, and explicitly, and regularly report on its performance, including classes of resources it is unable to maintain or to which it cannot currently provide access.
  • Develop and apply appropriate accessibility pathways for specific collections and formats. These pathways must:
    • provide access to the defined significant properties;
    • maintain evidence of authenticity;
    • comply with intellectual property rights and with other legal and moral rights related to copying, storage, modification and use of specific resources;
    • be cost-effective; and
    • support ongoing access and preservation over time.

At this stage, the Library believes it will need to use a range of approaches to maintain access to all the digital resources in its care. It assumes that format migration will be an effective pathway for large numbers of files in ubiquitous open standard formats such as image and audio files generated by the Library's own digitisation programs. On the other hand, pathways such as emulation of hardware or software, software archiving, and viewer migration will probably be needed for file formats for which there is no safe migration path.

Research

Current knowledge is not adequate to address these policy directions satisfactorily; needs will also change over time. Therefore, the Library will continue to encourage and undertake research into areas in which it requires more knowledge to support its decision-making processes. Such areas include:

  • The practicalities of storage, media refreshing and data transfer
  • Appropriate levels and kinds of duplication and redundancy of storage
  • Access pathways including migration of data between file formats; emulation of hardware and software platforms; maintenance of access technologies including access to required software; and data recovery
  • Appropriate levels of diversity in managing digital collections
  • Options for dealing with resource types currently not well represented in the Library's collections, such as email messages or database-structured resources
  • Emerging risks and strategies for dealing with them
  • Quality control issues.

Standards development

The Library believes that standards are a vital element in developing reliable archiving and preservation procedures. The Library will continue to support standards development in Australia and internationally where it appears to offer direct or indirect support to the Library's business needs.

Working with others to preserve the nation's digital information resources

The National Library is one of many players with an interest in ensuring the national documentary heritage is preserved and accessible. Others with such an interest may include State, Territory and University libraries; some public libraries; national, state and organisational archival agencies; museums; creators, publishers, and re-users of resources; information users; government, and the community generally.

The Library seeks to work with others who are taking, or could take, responsibility for preserving components of Australia's digital information resources. In working with such partners, the Library wishes to:

  • Identify appropriate partners and stakeholders able to contribute to a national effort
  • Establish agreements on responsibilities and roles
  • Pursue explicit, mutually-accountable agreements that provide a reliable basis for ongoing accessibility over long periods
  • Help identify, develop and promote policies, procedures and tools to support such an aim
  • Work with creators, publishers and re-users of digital content to encourage practices that will enable, rather than hinder, preservation
  • Work with governments to develop legislative and funding frameworks that will enable cost-effective preservation.

Working with others to foster digital preservation

The Library places great importance in working with others in Australia and internationally to develop practices, strategies and understandings in support of digital preservation. This is evidenced in the Library’s commitment to the PADI service, an international subject gateway on digital preservation. The Library seeks to:

  • Freely share information on its approaches, policies, systems, strategies, tools and experiences
  • Learn from the experience of others as well as its own experience
  • Maintain and improve mechanisms for comparing approaches and strategies, and for reviewing developments, through the PADI website. The Library will continue to seek a level of buy-in to PADI that will enhance its role as an internationally useful subject gateway
  • Participate in research and development projects where there is an identifiable benefit to the Library and to others involved in preserving Australia's digital information resources.

Contact

The Director of the National Library’s Preservation Services Branch is responsible for maintenance and implementation of this Digital Preservation Policy.

17 July 2001; revised 24 February 2002

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