ABSTRACT
The objective of this book is to promote a better understanding of the nature of SDIs and to assist practitioners to design more efficient and effective SDIs. It is hoped that it will also contribute to the growing body of knowledge concerned with SDIs and as such should also be useful for researchers and students of SDI. In writing and editing the book we had hoped to cover many if not most of the key issues in the evolving SDI concept. While we are satisfied that the book addresses many of the current SDI issues we also recognise that there are some current and evolving issues which have not been addressed. We have tried to identify these both throughout the book and in this chapter.
