The ease of distributed access accompanying the digital revolution has a darker side. Technological obsolescence and ephemeral formats have left little firm ground upon which to build the infrastructure necessary for the effective management and preservation of digital resources. An infrastructure supporting long-term access needs to be able to accommodate the continuous evolution of the technology as well as continuous streams of data. This means that a durable record of such work now includes a flexible and adaptable approach to maintaining live access.
Devices and processes used to record, store and retrieve digital information now have a life cycle of between 2 - 5 years, far less than some of the most fragile physical materials they are seeking to preserve. The practice known as 'refreshing' digital information by copying it onto new media is particularly vulnerable to problems of 'backward compatibility' and 'interoperability'. Software capable of emulating obsolete systems currently relies on the goodwill and enthusiasm of talented programmers but has little basis in economic reality.
The foundation of effective management of an ETD as digital resource occurs at the point of creation. How a digital resource is created and the form and format it is created in will determine how it can be managed, used, preserved and re-used at some future date. Authors/creators and migrators of all digital resources need to be aware of their importance to the life span or term of access of a digital resource.
Simple but practical strategies that might increase the life span of an ETD are as follows:
- do not assume any stability in hardware or software and try to record all the dependencies that support your ETD.
- Use non-proprietary formats such as (ASCII, Unicode or plain text) as much as possible (e.g. Notepad or Simple Text)
- Use widely available formats such as Word or PDF that can be easily converted into plain text
- Use widely available non-proprietary image formats such as JPEG or PNG rather than GIF (proprietary format)
- If you must use custom or proprietary software, make such you keep a record of the version number (e.g. Real Media 7) and all the hardware dependencies (e.g. MAC system 7).
This information can be stored within the metadata associated with your ETD. For example, you could use the Dublin Core metadata element, 'DC.Relation.Requires'. As technologies evolve, the use of preservation metadata to record this kind of information is increasing. Check with your library to see what standard is currently in use.
Next Section: Interoperability