Preserving Items At Risk
Risk assessment in regards to digital preservation means to examine the possibility of a data file becoming unreadable and thereby becoming lost forever. In preserving digital data there are three categories of potentially lost data:
1. Destroyed data
Where the data or bit stream is no longer intact, such as physical damage to a disc or tape containing the data. Recovering this type of data is either impossible or extremely expensive.
2. Unreadable data
Where the data resides on a medium, such as a tape or disc, that is obsolete. Or the data is in a format that cannot be read by current software or systems. Recovering this data is possible. It may require re-staging the original hardware / software platform, engaging the services of a programmer to extract the byte stream and transfer it so it can be used by current systems, or using the services of commercial data recovery firms.
3. Loss of format
Another category of difficult data, is where the data is recoverable, but the outward presentation of the data is lost. An example of this may be a document that was created in Word Star: it can be read by MS Word, but the document formatting is lost, so that the data is difficult to read or interspersed with control characters.
In all of these cases, it is easier and less expensive to preserve the data before it is unreadable. And to do this, we must predict what problems will arise and take appropriate and timely action. While this will be difficult in some cases, below are some guidelines to help identify what items are at risk. There are a number of examples of software programs and near-obsolete hardware that are used on campus where support is provided by the individual or the department. These may be currently viable, but the likelihood of data loss is increasing. Examples may be: Word Star documents; early versions of WordPerfect and MS Word; documents stored on 5.25 inch floppy drives.