Selection for Preservation in the Digital Age.

An Overview

In this article, I address three sets of issues. First, is digital conversion a preservation technique or is selection for digitization fundamentally an issue of access? Second, how does the process of selection for digitization differ from selection for traditional preservation activities? What selection criteria apply? Finally, what effect might digitization have on preservation as afield?

In this paper, I consider three issues: whether conversion to digital form is a preservation action, the contrasts between selection for digital conversion and selection for traditional preservation, and the potential effects on the field of preservation. All of these issues are under active debate by, among others, Atkinson (1998), Conway (1996b), Hazen et al. (1998), and Smith (1999). While consensus is growing, many points remain unsettled.

Is Digitization a Real Option for Preservation?

It is a given that in order to achieve preservation, we must provide a long-term version of at least the intellectual content of the item. Ideally we preserve the original object itself, appropriately repaired and properly housed. Driven by necessity in the form of irreversible deterioration, we produce surrogates. While it is of course impossible to guarantee permanent survival (O'Toole 1989), preservation relies on the use of stable media with long life expectancy, properly made and properly stored, to prolong the existence of the information.

Once created, permanent and durable paper copies and preservation-quality microfilm will endure for hundreds of years, barring disaster or vandalism. To date no one can prove that any digital version will survive and still be accessible beyond a few decades, despite much talk about migration and emulation, especially considering the repeated intervention these will require. Further, the accuracy and authenticity of a digital version may be open to question. Was the original object accurately and completely represented in the digital version at the time of image capture? Can we be assured of its authenticity over time--that is, can we be sure that it is still complete and has not suffered undocumented change? Lacking agreed-upon mechanisms for this assurance, and lacking longevity, digital copies alone cannot constitute preservation.

It is also a given that preservation without access is futile. Digitization offers enhanced, wider, easier access than microforms or photocopies, and it can capture color, sound, movement, and other features that traditional preservation reformatting has not handled well. The term "hybrid approach" (Willis 1992) expresses the idea that digitization in combination with traditional preservation activities provides a way to accomplish both sides of the preservation/access dyad: longevity via traditional means and improved use through digital means. We now have the option to microfilm an item, then scan the film (Conway 1996a); scan the item then produce computer output microfilm or print out to acid-free paper instead of making photocopies or copyflo (Kenney 1997); or we can scan the original item, retain it, and use the online version as a facsimile or surrogate to protect the original from unnecessary handling. All of this forms part of a continuum with preservation at one end and digitization purely for acce ss purposes at the other. The issue for selection is deciding when best to employ digitization.

Is the Process of Selection for Digitization Significantly Different From Selection for Traditional Preservation Activities?

The process of selection for traditional preservation reformatting and the criteria on which decisions are based are well established (see Williams and Lunde 1997 for an historical overview). The decision process is not linear. No single selection criterion suffices; it is only valid in combination with others, as the decision-maker steps through a series of complex, interconnected questions where each answer influences the others. Further, answers to these questions are situational. Given my institution's specific mission and history, is this item old enough, useful enough, important enough to keep? Given the size of my preservation budget and the number of items that need care, is it damaged or endangered enough to warrant expenditure? Selectors at different institutions frequently give different answers when faced with copies of the same book.

Physical condition drives traditional preservation decision-making. An item added to the collection sometime in the past is now in fragile, damaged, or threatened physical condition. We evaluate its value for continuing scholarship. Decisions follow to determine how preservation should and can be achieved, based on the item's value, its physical properties, and the nature of its current and anticipated use, as in the following criteria:

* Is the item or collection damaged or endangered?

* Does it have sufficient enduring value to justify preservation? This can include but is not limited to: artifactual features, e.g. bindings, illustrations; uniqueness or historic importance; distinguished broad or deep long-term intellectual content, with potential long-term value for teaching or research; consonance with the mission of the institution; and contribution to or support for historically important areas at the institution.

* Which preservation options are available, given the physical nature of the item or collection, and its current and predicted future use? Can we repair it? If not, can a preservation copy successfully capture its content, and support current and predicted future use? Are there factors like use of color, poor contrast, or missing pages that might make …