Introduction

This chapter covers the initial steps required to implement the principles just defined in a metadata strategy capable of practical application. Putting these into practice entails mapping out a canonical statement of metadata, an OAIS AIP, based on established standards wherever possible. It should be software independent and interoperable; this should extend to its syntax, semantics and content. It will include as an integral component a coherent and pervasive system of identifiers and will ensure that its records are themselves carefully curated in terms of preservation, authenticity and identification. The strategy as a whole should be capable of supporting all stages of the digital curation lifecycle.

Initial steps: standards as a foundation

There has been much emphasis in the preceding discussion about the importance of standards, and so particular consideration should be given to their place within an overall strategy. The benefits of employing standards are manifold: they include embedding metadata within best practices, ensuring no repeat of mistakes that have been ironed out as standards have been developed and enhancing the interoperable potential of a digital library's collections. They do, however, have the potential sometimes to distort the environment that we construct by over-rigidity or a poor semantic fit with its requirements.

The initial question to be asked, therefore, is how to embed standards within a metadata strategy.

Three approaches are possible here:

• • to take a metadata standard ‘off the shelf ‘ and apply it directly;

• • to map out a metadata architecture and then translate or serialise it to an established standard;

• • to devise a metadata scheme which is local to a digital library, possibly mapping it to established standards to make it easier to share with others.

‘Off the shelf’ standards

The simplest approach to employing an established standard is to implement it directly. This means, as a minimum, adopting its semantics, the fields that it defines, as the basic components on which a metadata strategy is built. DC, which will be discussed in detail in Chapter 7, is one which is widely used as a generic scheme for a diverse range of digital objects. Its 15 fields are broad enough to encompass most requirements and it is easy to learn – two factors which make it a good option for the semantics of a metadata architecture.