Information Technology Reference
In-Depth Information
responsibilities cover, but about access. The key question concerns how a user
can have confidence that the digital object which the archive provides to him/her
is authentic i.e. what it is claimed to be.
Chapters 10
and
13
contain a detailed
discussion of Authenticity. The phrase “copies of, or as traceable to” means
that the archive may keep the original bits and send a copy to the user, or it may
have performed various operations such as sending only a sub-set of the origi-
nal or carried out preservation activities, such as transformation, which change
the bit sequences, but will have to maintain appropriate evidence.
HOW
: The way in which digital objects are made available to any users are
many and varied. In fact access is the user-facing part of the archive where it
can make its mark and an immediate impression on users and potential users.
OAIS has very little to say about the types of access which may be provided,
nor does this topic have much to say about it beyond some points about Finding
Aids in
Chap. 17
. On the other hand Authenticity is the subject of
Chap. 13
which also contains many examples of the types of evidence which may be
provided by the archive and a number of tools which might be useful; it also
provides ways of dealing with the “as copies of, or as traceable to” requirement.
Dark Archives are those which hold digital objects but do not make them acces-
sible - at least not for some period or until some pre-determined trigger. These
archives can still be preserving the understandability and usability of the digi-
tal objects for a Designated Community but do not, during that “dark” period,
allow even the Designated Community to access them. During that “dark”
period it would not be possible, without special access being granted, to verify
the preservation of those digital objects.
6.3 OAIS Information Model
For convenience, the following repeats some of the material from
Chap. 3
, with
some additional explanations and examples.
6.3.1 OAIS: Representation Network
A basic concept of the OAIS Reference Model (ISO 14721) is that of information
being a combination of data and Representation Information as shown in Fig.
6.1
.
Interpreted
using its
Yields
Data
Object
Representation
Information
Information
Object
Fig. 6.1
Representation information
