Strategies for developing sustainable and scaleable digital library collections

Decisions taken when creating a digital information resource (e.g. about its contents, format, data model, level of description, etc.) impact directly upon how, at what cost, and by whom that resource can be used, integrated into collections, maintained, and supported. A somewhat more constrained set of ramifications stem from decisions taken to include third-party data resources into existing digital collections (whether by acquiring those resources outright or by acquiring access to them under some form of licensing arrangement).

One consequence for libraries that assemble digital collections from locally produced and third party data is a need for formal review procedures that help assess and cost the full ramifications of its decisions to create, acquire, or acquire access to a digital resource. Such procedures are both well known and well documented where paper-based and analogue materials are concerned. For those formats, review may emphasize potential use (demand), cost, and fit with existing holdings. Review may also take account of medium- and long-term storage, maintenance, and access requirements (especially with rare and special collections and with analogue materials such as sound, film, and video recordings) as well as any special conservation or preservation needs.

Although the same high-level concerns may govern assessment of a digital resource, detailed evaluation will differ considerably than that which applies to more traditional formats particularly where information access and maintenance issues are concerned. Here, the rate and pace of technical change, the volatility of digital media, and the implications that access licenses have for collection development and use forces fundamentally new kinds of review that concentrates, for example, on:

• hardware, software, and networking environments required to provide access a resource including investigation into the stability, maintenance, and potential migration of such environments;
• copyright and licensing issues and any associated system requirements e.g. maintenance of secure environments, charging mechanisms, etc.;
• methods and costs involved in maintaining access to a resource over the medium- and longer terms;
• development and provision of appropriate user support services; and
• the costs involved in accessioning a data resource into a collection, a process that may itself include data reformatting, metadata creation or amendment, systems design or modification, development of any documentation that may be required by end users, public service librarians, systems librarians, etc.

Formal review of potential data accessions takes on even greater significance for libraries and other organizations that have an interest in developing large-scale digital collections. Increasingly such organizations seek "core" technologies and services that promise, through their common application across a range of heterogeneous data resources, to integrate access to and the administration of such resources. Here the review process furnishes evidence not only of the likely costs involved in integrating a data resource into an existing collection but also of the viability of evolving core technologies and services.

Formal review procedures are as critical given the departmental organization of most libraries. Where digital resources are concerned at any rate, collection development decisions may have substantial impact on the work of departments concerned cataloguing, licensing and administration, public service and user support, and with library systems. Formal review procedures help to predict those impacts and in this respect act as a substantial aid in work-flow management. They may also mitigate against having to involve professional departments across the library in review of every data resource that may be considered for inclusion in a collection.

Naturally, the need for formal review procedures that can be applied in the development of digital collection has surfaced a variety of practices. These are typically available at an institutional level as guidelines that aid selectors, bibliographers, digital library professionals and others engaged in the development of digital collections. This publication series seeks to assemble, review and document existing practices and, where possible, to recommend the good or even best practices that emerge from that review. It is envisaged as a series rather than as a single publication in order that it may take account of the very different approaches that may be required in:

• the design and development of local digitization projects that create digital surrogates for information objects in some paper-based or other analogue format;
• the design and development of data creation projects that produce information resources that have no analogue equivalent and are in this respect "born digital";
• the selection of existing third-party data resources for inclusion in a collection either through their outright acquisition or by acquiring access under some licensing arrangement; and
• the development of Internet gateways comprising locally maintained pages or databases of web-links to third-party networked information resources.

The initiative also envisages the production of planning and development tools, for example, copyright clearance guidelines, template licenses, and outline work-flow plans.

Titles and associated planning and development tools that deal deal with digitization projects and with selection of existing third-party data resources are likely to be given priority.

The guidelines are intended to inform local decision-making rather than to prescribe practice. In this respect, they are intended as a starting point for the development of review procedures that are appropriate to an institution's specific collection development aims and capacities.

Clearly, the library needs ultimately to allocate its limited acquisitions budget effectively across a range of very different information resources including those listed above but also the more traditional paper-based and analogue formats. In this respect, it needs collection development policies that assist it in weighing the relative costs, benefits, and values that may be associated with these very different resource types. Although the guidelines intended for publication in this series will not supply that policy framework, they will, it is hoped, provide building blocks that are essential in its production.