Changes between Version 7 and Version 8 of CMDI 1.2/Resource proxies/ResourceRelation

Timestamp:

01/20/14 11:01:47 (10 years ago)

Author:

oddrun.ohren@nb.no

Comment:

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CMDI 1.2/Resource proxies/ResourceRelation

@@ -163 +163 @@
    }}}
    which adds a lot of power to the (resource) relation list but of course also complexity and another level of indirection. Is that roughly what you had in mind, Florian and Oliver? If so, the question is: is is it worth the additional hassle or should the 'part of' realation for metadata documents keep a special status.
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+Oddrun: 
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+We need to be clear when we are talking about n-ary relation with n>2 as opposed to a set of several binary relations. We also need to be clear on the semantics of the ResourceRelation element: Does one ResourceRelation element express one relationship only, or may it sometimes express several relationships as suggested by Oliver? 
+* If we constrain ResourceRelation to represent one relationship, and go for solution 2, it is possible to express realtionships of higher dimensions than 2. That is, each resource listed in the ResourceRelation participates in the same relation,for example,  any ResouceRelation with 3 resources represents a ternary relation.
+* If we allow one ResourceRelation to represent more than one relationship, I think in effect we limit the expressive power to binary relations. Oliver's example with 5 annotations of the same resource expressed as one ResourceRelation would then represent 5 binary relations. 
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+I think the first bullet (one ResourceElement = one relation) gives the most generic and extendible solution. Then we may or may not limit ourselves to binary relations, and it is easy to extend to higher dimensions later, if appropriate.
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+Using datcats for relationships and roles sounds like a good idea, but we should take care how we use them. The examples in the original text above show the difficulties, for instance:
+* DC-4009 is used to represent the relationship ''annotates'', but is defined in IsoCat as "The application of a scheme to texts...", that is, an ''operation/action'', not a relation.
+
+How strict should we be in applying datcats to relationships, - is it sufficient to select datcats conveying the general idea of the relation, or must the datcat be explicitly defined as a relation (as in the other example using DC-2318)
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