Book Review: Digital Preservation
Digital Preservation is a promising volume that will prove useful to information professionals wishing to learn more about digital preservation, particularly in a cultural heritage context. This edited collection offers perspectives and overviews of different aspects of preservation, such as strategies, costs and metadata, by a select number of widely acknowledged experts. Other chapters cover Web archiving and Web archiving initiatives, European approaches to preservation, and digital preservation projects from around the globe. Overall the book is an interesting, if somewhat segmented, read.
Chapter One provides a fairly detailed introduction to the subject of digital preservation. Written by editors Marilyn Deegan and Simon Tanner, this chapter acts as a springboard for subsequent chapters and encompasses some engaging and thought-provoking discussion of some of the key issues in digital preservation. Much of the chapter is fairly academic, discussing such issues as authenticity, surrogacy, data complexity, legal issues, and asset value, but this is a good stimulus for those approaching this subject anew to consider how these matters may be relevant in their own organisations. The chapter refers to numerous external initiatives and tools, including the Selection Decision Tree produced by the Digital Preservation Coalition and JISC/BL lifecycle collection management project (LIFE); it also offers sufficient references for readers later to locate external sources of information that provide more detail.
Chapter Two by David Holdsworth is a fascinating discussion of strategies for digital preservation. The chapter does not focus on the traditional options for preservation strategies - namely migration, emulation, printing to paper and technology museums - perhaps because these are already explored in Chapter One. It offers instead a more technical overview of a specific approach developed by Holdsworth and colleagues over a number of research projects. This rather technical approach, which is integrated with certain aspects of the Open Archival Information System (OAIS) reference model, requires preservation of original data objects as byte streams alongside sufficient representation information to enable the significant properties of the object to be rendered as an integral whole at a later date. Although efforts have certainly been made to make this chapter widely accessible, it is without doubt the most technical chapter in the book and certain elements may to be too technical for readers without practical and technical experience.
Chapter Three explores a very different facet of digital preservation, that of preservation metadata. Authored by Robin Wendler, the chapter provides readers with an overview of the state of the art in preservation metadata within the digital library community. Much of the thinking in this chapter appears based on the author's own experiences with preservation metadata research, particularly development of the PREMIS preservation metadata data model and dictionary. This is no bad thing. The chapter also introduces a number of related metadata standards and initiatives for different preservation purposes and different types of digital objects.
Chapters Four and Five are dedicated to archiving a particular type of digital resource: Web sites. Chapter Four by Julien Masanès identifies the characteristics of Web sites as a particular digital resource type, and describes some strategies for collecting and storing Web content. Discussion of preservation per se is minimal, perhaps because most Web archiving activities have not yet reached the stage where preservation actions (for example, migration to combat obsolescence of downloadable files such as hosted text documents) are in place. Chapter Five by Elisa Mason introduces some of the main international initiatives in Web archiving, including the PANDORA archive at the National Library of Australia, the UK Web archiving initiative UKWAC, the Kulturarw Project to harvest and collect Web sites from the National Library of Sweden, the Minerva Web preservation project at the US Library of Congress, the Internet Archive, and the International Internet Preservation Consortium (IIPC). This is a brief yet useful overview of the main Web archiving initiatives and tools.
In Chapters Six and Seven, Brian F. Lavoie and Stephen Chapman offer complementary perspectives on digital preservation costing issues. Lavoie discusses valuation and costs of digital preservation activities, with particular attention to how different strategies may impact on final costs. Whilst it cannot offer any final answers on how much digital preservation will cost, this chapter does provide the reader with useful and broad-ranging insight into the factors that may affect digital preservation costs. Chapman on the other hand, approaches the issue of digital preservation costs from a repository-based perspective, discussing different repository preservation service models and arguing that money must be made available to meet the challenge of preserving digital content.
In Chapter Eight, the book moves away from examining specific aspects of preservation and explores whether there is a particularly European approach to digital preservation. Peter McKinney provides here a thoughtful overview of the European digital preservation landscape. A select number of European projects are discussed, alongside the role of the European Commission as a funding and motivating body, and McKinney recounts some experiences acquired during the course of the ERPANET Project. Finally, Chapter Nine by Jasmine Kelly and Elisa Mason provides brief overviews of over fifty digital preservation projects or initiatives from around the globe. An extensive bibliography and list of references is also included, comprising a mix of Web sites, Web-accessible papers and print-only reports.
The main advantage of the book is its identification and discussion of some of the main issues in digital preservation, alongside an introduction to several national or international initiatives that address the problem. This is not a book for digital preservation professionals; rather it is aimed at information managers, archivists and librarians, as well as others in the information and cultural world such as museum curators and students, who perhaps are already acquainted with some of the problems in digital preservation but need to increase their knowledge and understanding of main issues and current developments. It is not, however, and does not claim to be, a practical manual, and should not be purchased with that expectation. However some chapters do go some way towards solving specific problems that people may face in a given situation. Overall, the book is a useful introduction to the multi-faceted nature of digital preservation and explains in varying detail the complexities of some of the issues that preservation encompasses.
The book has the advantage of providing a range of views from acknowledged experts in their given field, but suffers to a degree in terms of focus and continuity of thought. This is to be expected from an edited anthology and it would be unreasonable to expect an edited work to be singing entirely from a single hymn sheet. Deegan and Tanner do an admirable job in providing an initial and broad overview of the digital preservation challenge, which essentially gives readers a basic grasp of the issues and arms them with sufficient knowledge to understand subsequent chapters. Yet there is little to bring together the subsequent individually authored chapters into a coherent whole, and future editions of the book would benefit from a conclusion to address this. The promised 'case studies' referred to on the back cover are also somewhat disappointing: they do not go into great depth about the projects or initiatives they describe and are more of an introduction to archiving or preservation initiatives rather than preservation in a given institution or setting.
As is common with published works from a dynamic field, the fast pace of research and developments in digital preservation mean that some sections of the book have already begun to date: aspects of the chapters on preservation metadata and European approaches to digital preservation, for example, could already benefit from updating. Furthermore, given the high profile and prolific rate of publications from many of the contributing experts, it is perhaps inevitable that information on several of the subjects discussed can also be found freely on the Web. Despite this, identifying and discussing these issues as part of a collected and edited anthology should still be valuable for those who are new to the subject; and for those who wish to learn more about the current state of affairs and the main issues and trends in contemporary digital preservation. The book remains valuable as a reflection of the state-of-the-art in digital preservation knowledge at a given period and is to be recommended for information professions who are not experts in the area but wish to develop their knowledge of the issues further. This book will certainly enable them to do that.