background image
215
The following graph depicts the increasing complexity of long-term preservation
with regard to the level of content abstraction:
The higher the level of content abstraction, the higher the loss of information and
finally, the more complex the question of preserving digital material successfully.
Undoubtedly, capturing content at the knowledge level substantially increases the
complexity of long-term preservation.
Fixity and Context
Integrity of digital information is also compromised by the lack of fixity, i.e. the ease
with which digital objects can be altered, changed or duplicated, without leaving traces that
the original resource has been corrupted. On the Internet, the issue of digital objects not
being fixed multiplies with the increase of web sites that offer dynamically created content
from databases. Such dynamic digital objects are even more transient than real objects or
their digitised counterparts.The only way to fix those cultural heritage resources in time, is
to take a snap shot of the database.
Closely related to the problem of fixity, is the issue of context and the fact that the
integrity of information objects is also dependent on how they relate to other objects in the
digital environment. For long-term preservation, the archiving organisation also needs to
capture the context of a digital cultural resource. On the World Wide Web, however, where
objects are placed in relation to other objects through hyperlinks, capturing the context can
create a major problem. How much of this context should be preserved together with the
actual digital object? As Jennifer Trant, Executive Director of AMICO, USA, points out:
"What does it mean to preserve a search engine as of a particular date this might imply
preserving the whole web." (DigiCULT Delphi, July 17, 2001)
With born-digital objects, it is not always possible to "preserve all aspects of `look and
feel' as opposed to some sort of abstract information content.This can be crucial in some
works, and even could prevent digital preservation activities for some art works where the
look and feel is defined and required by the artist." (Chris Rusbridge, University of
IX TECHNOLOGY
Text
Macro
programming
Dynamic,
hyperlinked
objects
Interactive
MM
Future
information
objects
Bitstream 0/1
Migration
Emulation
Potential
data loss
Level of
abstraction
Complexity of long-term preservation
Format & Structure
Knowledge & Relationships
Preservation
complexity
Sour
ce: Salzburg Resear
ch, 2001