Long-TermPreservation of Digital DataEds. Borghoff et al.
In simple and elegant way, authors of this book target a broad audience from widespread disciplines with a common interest, namely the interest in a long-term archival storage, and with a common fear, namely the fear of a future where the digital heritage is lost. How do we preserve data for future generations, is dealt in a subtle way. Ancient tomes require expensive preservation measures and works printed on paper having a high aggressive chemical content can be saved from destruction by storing them on microfilm. Digital media has made this process simple and attractive But, ‘Will this digital media be available in 50 years and will there be a machine capable of reading it (and presenting it in a form for humans to perceive and understand)?’ is the question. The cave paintings, though thousands of years old, are preserved in the same manner with the same sense organs as those of the artist but the contents of the text files from a computer become legible for us only indirectly with the aid of a suitable computer system since digital media are not directly readable by humans. So the question of compatibility too arises. In addition a plethora of different editors for composing digital documents have been developed; (for text, graphics, spread sheets, foils, web pages and other purposes) each with its own proprietary format. The problem of preserving such heterogeneous digital data applies not only to libraries and institutions that are legally obliged to preserve their inventory, but also to everyday life, where digital data is commonly used to store information. This book offers the readers enough arguments (a) to understand that now is the time to act, (b) to feel where current development is, and (c) to have a presentiment of where the research is going. Experts in the field may find the book useful as a compendium on long-term preservation. The first part comprises seven chapters where the methodological overview is presented.Chapter 1 illustrates the general problem of long-term preservation and with an introduction to the most important technical approaches: migration and emulation. The problems of durability of electronic storage media as well as the dependence of digital documents on specific software necessary for their interpretation are addressed and delve further into the causes of these problems and discuss relevant terms and concepts. Legal and social questions, which must be answered on the way to a comprehensive solution for the archiving problem of digital documents, are also discussed here.Chapter 2 introduces the OAIS Reference Model and explains the so-called DSEP process model, which is also based on the OAIS Reference Model, but is more adapted to the specific needs of electronic libraries.Chapter 3 illustrates different options for the migration process based on real-life examples, gives a succinct definition for the migration process itself and highlights its overall goals with an interesting microfilm approach that rounds off the chapter. Chapter 4 introduces information technology (IT) terms and techniques that are relevant to the emulation approach. The chances and risks of the emulation approach are summarized briefly. Chapter 5 shows how markup techniques and metadata are used in the field of long-term preservation are described. Their respective advantages and disadvantages when applied to long-term preservation in digital libraries are surveyed.In Chapter 6, two typical procedural document description languages (TIFF and PDF) and two structural document description languages (HTML and XML) and RDF, Topic Maps, and OWL for defining ontologies and the vision of future Semantic Web are explained.In Chapter 7, the need to establish institutions that are able to take care of long-term preservation in a systematic and sustainable way is explained and an approach that combines the most importanttechniques for long-term preservation in such a way that they complement one another advantageously is expressed.The second part consists of four chapters where relevant national and international projects are discussed. In Chapter 8, the description of metadata sets and the markup aspects of recent preservation projects are reviewed. The Dublin Core Metadata Initiative (DCMI) and Metadata Encoding and Transmission Standard (METS), the VERS project, the Text Encoding Initiative (TEI), XML and the activities of the Research Libraries Group (RLG) and also Pandora is reviewed.Chapter 9 demonstrates migration using four example projects while Chapter 10 discusses recent studies and experiments of using emulation for long-term preservation. Chapter 11 supports decision makers. A catalog of criteria that makes product features transparent and comparable. The derivation of functional and nonfunctional criteria is described in detail. The chapter concludes with the complete criteria catalog applied to some product offers. In short, this book addresses the problem of preserving digital data for periods in excess of 50 years addressed as ‘long term’. the topic may seem something very common in the field. But what makes this book special is the presentation (with keywords of each paragraphs in the margins) and the simple and catchy narrative style adopted by the authors that make this book stand out.