Digital Preservation Coalition

Organisational Activities - Acquisition and Appraisal

Appraisal and Selection

In a digital environment, decisions taken at creation and selection have significant implications for preservation.The link between access and preservation is far more explicit than for paper and other traditional materials, as access to a digital resource can be lost within a relatively brief period of time if active steps are not taken to maintain (i.e. preserve) it from the beginning. As the interactive Decision Tree indicates, if it is neither feasible nor desirable to preserve a digital resource across various changes in technology, then its acquisition should be re-evaluated.While many of the same principles from the traditional preservation environment can usefully be applied, policies and procedures will need to be adapted to the digital environment. In a print environment, the decision to select, and the decision to preserve, can be taken quite separately and within a timeframe which may span several decades.The brief period during which digital resources will inevitably become inaccessible means that it makes sense to make decisions about selection and preservation simultaneously.

While this may mean that greater rigour is required in selecting digital resources than for printed or other analogue material, it will avoid costs which will otherwise occur further down the track as retrospective preservation of digital resources is not recommended. In these cases, as the digital resources become inaccessible, the only pragmatic option is likely to be to de-select, an activity which is in any case not without cost and one which should preferably occur as a result of a conscious decision based on sound policies, rather than by default.

Accurate documentation is also crucial in the digital environment.This will provide not only essential details for managing the resource over time but also information on context without which there may be little point in preserving the digital object itself even if it is technically feasible to do so. In the accompanying Decision Tree, it is suggested that acquisition be re-evaluated if documentation is inadequate.

In the case of networked digital resources, where providing access to a resource does not necessarily require bringing the resource physically into a collection, the concept of acquisition is quite different from traditional collections.There are a range of options available to provide access or to build 'virtual collections'. For example, making copies/mirrors for access, providing a hyper link to a resource, online catalogues and finding aids.

Whereas acquiring a resource in the non-networked environment usually implies keeping it, in the networked digital environment, it is possible to provide access to a resource without undertaking any preservation commitment either short or long-term. A number of institutions have adopted a selection policy based on levels of acquisition. For example, the Berkeley Digital Library sunsite (DLM Forum 1997) adopts four levels (Archived; Served; Mirrored; Linked), the AHDS (Tanner and Lomax-Smith 1999) have articulated five levels (Archived; Served; Brokered; Linked; Finding Aids); while the National Library of Canada (PRO 1999) has three levels (Archived; Served; Linked). Adapting policies to the digital environment in examples such as these is likely to be the most cost-effective means of ensuring appropriate management and continued access to the most important digital resources. In practice adopting collection levels and being explicit about preservation commitments is a crucial element of preservation policy and procedures.

In a digital environment acceptance of preservation responsibility implies significant costs. On the other hand, failing to consider short and long-term access at selection is likely to mean loss of the resource shortly after acquisition. In some cases (potentially many cases for electronic publications), an institution may be reluctant to take primary preservation responsibility for materials it acquires if it feels that interest in its preservation is so widely shared that it would constitute an unfair burden on their own institution. This emphasises the need for collaboration between institutions and the need to establish equitable agreements for shared efforts where necessary. The accompanying Decision Tree for appraisal and selection is based on the assumption that the resource has not yet been acquired and indicates a number of points at which cost implications will need to be taken into account before the decision to proceed with acquisition. It suggests that, at these points, difficult decisions may need to be made about whether the resource justifies the costs required or whether it is preferable not to proceed with acquisition.