In this digital world we are increasingly creating, storing, and publishing material entirely in electronic forms. While this is great for the trees and other resources used in making paper, it introduces new challenges in the process of collecting and preserving materials.
The preservation needs of paper are pretty well understood. Guidelines for ideal environments (heat and humidity) and practices (handling and storage) have been in constant refinement for hundreds of years. The libraries, archives, and information science communities only began thinking about preservation for digital material comparatively recently. This first post of a three part series on digital preservation will take a look at the challenges unique to preserving digital materials, and why we must approach digital preservation differently than physical preservation.
What might be surprising to many is the relative fragility of digital assets. Estimates put the average operation life of conventional digital storage media at five years. These failures occur in more than just the physical components: magnetic media are sensitive to anything generating a magnetic field from batteries to the sun! Optical discs can suffer from manufacturing errors or material degradation making them unreadable. Additionally, once damaged, a digital resource is often completely lost. Physical material might be salvaged through conservation. Recovering digital assets after damage is much more difficult.
Complicating the practice of digital preservation is the fact that digital materials are meaningless without the correct hardware and software environments to render them. Consider a printed book. The information conveyed by a book is encoded with ink marks made on paper. So long as the rules of the encoding language (that is, the language it is written in) and the marks on the paper persist, the information in the book can be recalled. The ink won’t independently leave the paper and reorganize into different patterns and structures.
This is exactly what happens to digital information. The long strings of characters encoding digital assets is only intelligible to a narrow band of both software and specific hardware configurations. Many of us have likely encountered the situation of being unable to open an old file in a newer version of software. Software developers are constantly adding and removing features to their products, often with little attention to backwards compatibility. Merely storing the digital encoding (or bitstream) is meaningless without also storing instructions on how to rebuild it back into an understandable, rendered product.
These extra considerations compound when you consider the speed of technological advances, and the new behaviors and interactive experiences we’re building and sharing with our machines and networks. Even identifying what behaviors and functions of digital assets are important to intellectual understanding of the resource is a quagmire. Those of us thinking about digital preservation have ceded a pretty large head-start, and the race is constantly accelerating.
In the next posting of this blog series, I’ll cover some strategies currently being used by the digital preservation community. I’ll finish this series with a post what you can do yourself to safe-guard your digital works and memories.