Introduction

In this chapter we begin to move from what metadata is in the abstract towards its application in practice. It is at this point that we should begin to think at a relatively high level about the basic principles to follow when devising a metadata strategy; we will then attempt in the next chapter to translate these into the first steps towards their implementation. By starting our planning at this relatively abstract level we should be able to keep in mind a picture of how metadata fits into the workings of a digital library in both the short and long term.

Principle 1: Support all stages of the digital curation lifecycle

We saw in Chapter 1 that one of the key principles that makes a digital collection a digital library is the concept of curation. Digital curation shares many features with its analogue counterpart, including its emphasis on selection, description, the provision of access and preservation; it also presents the librarian with multiple additional challenges because of the nature of the digital medium itself. The digital object, whether it is a book, video, audio or image, is opaque to the user in its raw state, a stream of binary digits: it needs decoding to render its contents visible and accessible. It is stored on media which have nothing like the proven longevity of paper, and so requires a carefully designed and applied set of procedures, such as regular copying to new stock, to preserve it. It is easily copied and transformed in ways which may nullify its integrity, and so often requires some form of digital rights management to protect the intellectual property of its owners.

The complex requirements of digital curation make it essential to devise an overall framework for all of the processes required to carry it out. Several high-level conceptual models have been designed to map these and put them into a coherent and, hopefully, easily understood form. These form something of a template for the design of a working system and a checklist to ensure that no essential components are missing from it.

One of the best known of these is known as the DCC Curation Lifecycle ModelC, so named after the UK's Digital Curation Centre, which originally devised it. Figure 3.1 shows the model expressed in graphical form.