On 13/09/13 23:32, Meehan, Thomas wrote:

> However, it would be more useful, and quite common at least in a bibliographic context, to say "This book does not have a title". Ideally (?!) there would be an ontology of concepts like "none", "unknown", or even "something, but unspecified":
>
> This book has no title:
> example:thisbook dc:title hasobject:false .
>
> It is unknown if this book has a title (sounds undesirable but I can think of instances where it might be handy[2]):
> example:thisbook dc:title hasobject:unknown .
>
> This book has a title but it has not been specified:
> example:thisbook dc:title hasobject:true .

The root of the cure here is having a model that defines the exact 
semantics of the RDF tags you're using.

For example the FRBRoo model, to assert that an F1 (Work) exists 
logically implies the existence of an E39 (Creator), an F27 (Work 
Conception), an F28 (Expression Creation), an F4 (Manifestation 
Singleton) and an F2 Expression, as well as two E52 (TimeSpan)s and two 
E53 (Place)s. See 
http://www.cidoc-crm.org/frbr_graphical_representation/graphical_representation/work_time.html

The bibliographer / cataloguer need not mention any of these, unless 
they wish to use them to add metadata to the F1 or to connect them with 
other items in the collection.

cheers
stuart
-- 
Stuart Yeates
Library Technology Services http://www.victoria.ac.nz/library/