Information Technology Reference
In-Depth Information
However if neither (1) nor (2) are available then one of the other methods must
be used, as would be the case for data rescue (in the sense of data inherited without
adequate “metadata”.
6.3.3 Representation Information vs. Format
To simply give the format of a piece of digital information is inadequate to com-
municate information, as a simple counter-example shows. Suppose that someone
gives you a piece of digital data and tell you that it is MS Word version 6 format.
This enables you to find the right software to display the contents. However when
you do that you see the following text:
sfqsftfoubujpo jogpsnbujpo svmft
To understand what this means, one must be supplied with the additional infor-
mation that a simple alphabetic substitution cipher (a
→
b, b
→
c etc) with spaces
unchanged, has been used.
With that additional information we can find out that the message is:
representation information rules
One should be suspicious of any discussion of digital preservation
which talks only about formats, with no mention of semantics or other
types of Representation Information.
6.3.4 Information Packaging
Another part of the OAIS Information Model is related to packaging. The reason this
is important is because the digital data is almost never “naked”. In other words it
might be a file in a file system and that may seem “naked” but in fact the computer
operating system has to be able to recognise it as a file and hence it cannot be
completely “naked”. This is even more evident when one is transferring data from
one place to another.
