Re: Open Library and RDF

Tom and others
 
FRBR will almost certainly declare the classes Work, Expression, Manifestation,
and Item as disjoint. All associated WEMI properties will have a domain of one
of these classes. The RDA model is based on FRBR, so a logical contradiction
will result if the subject of instance triple associated with a Work is the same
as the subject of instance triple associated with an Expression, etc.
 
Cheers
 
Gordon
 

On 14 August 2010 at 20:03 Thomas Baker <tbaker@tbaker.de> wrote:

> Hi Jeff,
>
> On Mon, Jul 19, 2010 at 06:02:59PM -0400, Young,Jeff (OR) wrote:
> > IMO, the term "Creator" implies a class name. In contrast, "is the
> > creator of" or "was created by" implies a property. I promise not to
> > whine if "creator" is defined as a property, but only if its range is a
> > class named "Creator". ;-)
>
> Hmm, I would argue that it is unnecessary and perhaps even
> counterproductive to create a class named "Creator" :-)
>
> The Dublin Core property dcterms:creator, for example, has
> a range of dcterms:Agent, not Creator.
>
> What if a given member of a Creator class were the Subject
> of a book, or its Translator or Illustrator?  Triples
> saying that that person is _essentially_ of type "Creator"
> (or Subject or Translator or Illustrator) could muddy the
> waters: an Illustrator has translated this and been the
> subject of that...
>
> To my way of thinking, in the example above, it is better
> simply to use a property to establish a creation relationship
> between a given person and given resource.
>
> I'm not entirely up-to-date on the RDA-in-RDF discussions but
> I have the impression that this still is an issue there too.
>
> Are there thought to be things that are _essentially_ members
> of a class Manifestation, and others _essentially_ of a class
> Expression, such that it would a logical contradiction in
> terms of the RDA data model if a given resource is asserted
> to be a member of both the class Expression and the class
> Manifestion?  If so, can we be confident that RDA-trained
> (or non-RDA-trained) catalogers will use the classes so
> consistently that contradiction need not be feared?  Is it
> not enough to describe manifestions in a certain way (i.e.,
> with certain properties) and expressions in another?
>
> More generally, if "A hasFriend B", is B essentially a member
> of the class "Friends"?  "Friend" with respect to whom?
> ("Creator" of what? "Manifestation" of what?)
>
> The point of modeling style is that it can be expressive
> enough to let the constellation of relations (RDF properties),
> within which a resource is embedded, define that resource --
> in effect to describe things more with verbs than with nouns.
>
> Maybe we need a Strunk-like "Elements of RDF Style":
> "Omit needless classes!" "Vigorous modeling is concise!"
> "Do not explain too much!"... :-)
>
> Tom
>
> --
> Thomas Baker <tbaker@tbaker.de>
>
>