Introduction

The work of the librarian has always called for an advanced level of proficiency in metadata. The imperatives of building, developing and managing collections and making their contents accessible have invariably obliged librarians to stay at the forefront of its developments. In the digital library the complexities of handling intangible objects recorded in binary digits on opaque media present new challenges and make additional demands on metadata's role and functions. The particular challenge which the strategy outlined in this book attempts to meet is to reconcile the diverse and complicated metadata needed to accommodate these requirements with the complementary obligation to produce a coherent overall environment which can be easily managed in the present and preserved well into the future.

The first part of this concluding chapter summarises the strategy and its array of interlocking components. The second part draws some general conclusions about metadata and its central place in the digital library.

The strategy in outline

The basic principles of a metadata strategy (Chapter 3)

The eight fundamental principles which underlie this strategy are the following.

• • It should support all stages of the digital curation lifecycle, such as those outlined in the DCC Digital Curation Lifecycle Model.

• • It should support the long-term preservation of the digital object, preferably within the context of the OAIS model, and should aim to create a ‘canonical’ version of a digital object's metadata, an AIP as defined in the OAIS scheme.

• • It should ensure interoperability at both a syntactic and a semantic level.

• • Metadata content should be controlled wherever possible by the use of cataloguing rules, name authorities and subject thesauri.

• • It should be independent of any given software application, especially a proprietary one.

• • It should apply a consistent and logical system of identifiers to ensure that every data and metadata component is unambiguously labelled.

• • It should employ standards whenever possible to enhance interoperability and avoid ‘reinventing the wheel’.

• • It should ensure the integrity of the metadata itself, for instance by recording details of its provenance.

Standards and identifiers (Chapter 4)

Standards should underlie a metadata strategy whenever possible. They can be implemented in three ways.