Implementation of these digital preservation principles will be contingent on the infrastructure provided by the Library and the availability of cost-effective solutions. These are influenced by expected rates of growth in the size of the Library’s collections, changes in technologies, and infrastructure replacement cycles. In implementing this policy with regard to its own collections, the Library will seek to apply certain principles.
With regard to costs and resources, the Library:
- Recognises that preservation action is an inherent cost of collecting (unless there is an explicit intention not to preserve), and seeks to understand the costs associated with appraising, acquiring, managing and maintaining access to digital collection materials;
- Attempts to allocate adequate and appropriate resources and infrastructure for sustained preservation action, but may need to tailor its collecting programs to take account of the ability to preserve and the availability of resources to do it; and
- Attempts to ensure sufficient trained staff are available to manage the processes required to preserve our digital collections.
With regard to methods, the Library must be able to:
- Assist collection areas with analysis and assessment of digital material during the acquisition phase;
- Understand what it holds in its collections;
- Understand what its preservation intentions are for every digital object and what is required to realise those intentions;
- Understand what is required to provide access, if there are any inhibitors to access, and the current level of support the Library is able to provide;
- Evaluate and monitor the degree of risk arising from collection composition, preservation intentions and available level of support within the Library for digital collection content, and monitor for risk conditions arising during general Digital Library operations;
- Anticipate the effects of changes in support;
- Recognise planning triggers, and plan and take appropriate action on a scale appropriate to the size of the target; and
- Audit the effectiveness of its preservation arrangements and modify the arrangements if necessary.
Systems and arrangements to address these preservation challenges must enable Library staff to deal efficiently, effectively and accountably with billions of objects, in diverse formats and collection contexts for access in wide ranging end user environments. Such systems and arrangements will need to support mass processes while offering the necessary flexibility to tailor both large- and small-scale preservation actions.
With regard to coordination and planning of the Library's preservation efforts, we will:
- Take actions based on summary reports of digital content (composition and characteristics of our digital collections), metadata characteristics and risks across collections or defined sets of managed content;
- Compare technical metadata, preservation intent, significance and defined risks for managed content, in conjunction with detailed reference information and resource inventory knowledgebases (e.g. information and associations between file formats and versions, software, hardware and levels of support) to evaluate risk and prioritise preservation planning and action;
- Aim to plan our preservation action proactively, providing sufficient lead time for appropriate infrastructure to be put in place to support the required action;
- Will consider the following broad preservation action approaches that are likely to be required:
- Format migration at the point of collecting;
- Format migration on recognition of risks;
- Format migration at the point of delivery;
- Emulation of various levels of software and hardware environments;
- Maintenance or supply of appropriate software or hardware;
- Documenting known problems for which no other action can be taken; and
- Deaccessioning or deletion.
We expect to use a range of approaches to maintaining access to all the digital resources in our care. The Library will choose the most appropriate approaches to achieve our preservation objectives.