Chapter 1: Introduction
A substantial part of the information that we create and process in everyday life exists in digital form only. The major difference between such information, e.g. represented in data stored on a hard drive, and the information embodied in the text on the printed page of a book, is that the latter information is directly accessible for us as human beings. In order to perceive the information represented in the digital object, however, we are in need of additional means. For the correct rendering of a book stored in the PDF format, for instance, it will first of all be necessary to be in possession of the right software. The execution of that software presupposes the corresponding operating system, which then in turn necessitates a certain hardware configuration to run properly. Over time, all of these layers are prone to errors that can lead to the loss of data and thus information. One reason for data loss is the obsolescence or destruction of data carriers or reader devices. As technological progress in this area moves at a particularly rapid pace, another cause that can render the content of a digital object inaccessible is the obsolescence of the corresponding software or data format. The loss of information represented in data might, moreover, occur despite of the availability of a functioning data carrier and reader device, when context that is needed to interpret the data properly is not (or no longer) available.