During the last months we at the KB in Holland studied the Premis Data
Dictionary. In our e-Depot we use metadata, but when we started with the
e-Depot the Premis Data Dictionary did not exist. So a comparison was
made between the Premis data elements and our e-Depot system (DIAS from
IBM). Our DIAS system will be upgraded to the next version so it is a
good opportunity to study the data model . Most of the Premis elements
will be relevant for us too. However some questions were left and I
would like your opinion on the following:
1. Premis definition of Representation: a set of files, including
structural metadata, needed for a complete and reasonable rendition of
an Intellectual Entity.
DIAS principle is 1 object = 1 AIP. If an object has a relation with
other objects the relevant information in the bibliographical metadata
will create the Intellectual Entity. So Representation Information will,
as far as we know now, always concern one object.
2. Preservation Level:
At this moment in our DIAS system all objects have the same preservation
level, we do not make a distinction. This might change in the future. As
a result of our study into migration we have some new thoughts and I
would like to share them with you. We think that it will become
important to register information about the 5 main characteristics of an
object (content, context, structure, behaviour and appearance) and to
add the preservation level of each of these characteristics. We have not
decided whether we would like to do this on object level (hardly
possible) but we think in terms of "class of objects "and "collections"
with a certain set of characteristics that should be preserved, for
example a collection of pfds where the text is more important than the
illustrations opposite to a collection of pdfs where the font of the
text is of no importance but the illustrations are.
I must confess these are thoughts and we are still discussing it.
3. Representation: creatingApplication
In my opinion this element belongs to the File section and not to the
Representation section, as it is the Application that created the file,
despite the representation of the file.
4. Representation and File; "use of an object"
In both Representation and File the expression "use of an object"
appears frequently, sometimes in connection with modifying the object by
the end-user. To me it is not clear what is meant by "the use of an
object". In our current situation we do not see any other use of the
object than an end user who is allowed to see or read the object
(perhaps download it but that is use outside our e-Depot). As curators
of the e-Depot we also "use" objects, for migration and emulation for
example. That is the only use we can think of. Did we miss a point here?
5. Representation: linkingEventIdentifier
According to the explanation of this element, events like format
validation and virus checking may be registred here. In our opinion this
is not Representation information but File information.
6. One practical point: I numbered all the elements (1, 1.1, 1.1.1 etc),
which make them easier to trace in the Dictionary.
I look forward to your reactions and will thank you very much in
Digital Preservation Officer
PO Box 90407
2509 LK Den Haag, The Netherlands
+31 70 3140109
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