Preservation Activities

OAIS identifies the general types of activities needed to preserve information as things, such as technology, environment, tacit knowledge, change.

As described elsewhere, given that LABDRIVE ensures that the bits can be kept unchanged by the archive system, there are a limited number of basic techniques for preservation, but each has a large number of ways in which to be implemented. At any point in time one or other basic techniques and options may be selected depending on estimates of costs and risks at that time.

The Data Object of the information being preserved may be:

1. kept by the archive unchanged; or

2. Kept by the archive but may be changed; or

3. not kept by the archive, but instead handed on to another archive.

Each of these three imply the following:

• In case 1) the archive may add Representation Information to ensure the Content Information is Independently Understandable. This might be needed if there are changes in the Knowledge Base of the Designated Community.

• In case 2), for example where option (1) is not possible/practical, the archive may Transform the Data Object of the Information being preserved, creating a new Data Object, keeping the original unchanged. The Representation Information Network must be changed, particularly the Structural Representation Information. In addition the Provenance Information of the new Data Object must include details of how this was derived from the original Data Object(s). The checks on the Transformational Information Properties must also be added to the Provenance. The orignal Data Object will normally be preserved unchanged.

• In case 3), which may be necessary if the archive is not able to carry out options (1) or (2), or if the archive is closing down, or must reduce its holdings because funding is being reducing, the archive may hand over the AIP which contains the Object being preserved.

Preservation activities such as these may not be needed for much of the time, but since one must expect things to change over time, one or other option will be needed from time to time.

Some examples are given in the following sections.