Yves Raimond wrote:
>> Ontology modularization is
>> a pretty difficult task, and people use various heuristics for deciding what
>> to put in the subset being served for an element. There is no guarantee that
>> the fragment you get contains everything that you need.
> Sorry, just jumping on that, as this is something I am having quite a
> lot of troubles to understand (and since quite a long time). Maybe I
> am missing something obvious, but how does using owl:imports avoid
> this randomness? When using it, you're still hoping that dereferencing
> the object of owl:imports will get you the relevant information? I
> agree that owl:imports allows you to commit to a whole ontology
> instead of committing to single terms within an ontology, but I would
> argue that in most cases, you just want to pick a few terms in an
> ontology.
There is no safe way of importing only parts of an ontology, unless you 
know that its modularization is 100% reliable.
Serving fragments of likely relevant parts of an ontology for reducing 
the network overhead is not the same as proper modularization of the 

Thus, you should import the ontology only, and not the fragments served 
via the dereferencable IDs of selected ontology elements. Partial 
commitment would require that there is a proper definition of the part.
> For example, I may agree with the way OWL-Time models
> time-zones etc., but I don't agree with the way it models time
> intervals vs. events.
If that ontology has two explicit parts, e.g. time-core and time-full, 
then you can commit to each one individually. If not, I would strongly 
discourage committing to a random fragment only.


martin hepp
e-business & web science research group
universitaet der bundeswehr muenchen

phone:   +49-(0)89-6004-4217
fax:     +49-(0)89-6004-4620
www: (group) (personal)
skype:   mfhepp 
twitter: mfhepp

Check out the GoodRelations vocabulary for E-Commerce on the Web of Data!


Talk at the Semantic Technology Conference 2009: 
"Semantic Web-based E-Commerce: The GoodRelations Ontology"

Tool for registering your business:

Overview article on Semantic Universe:

Project page and resources for developers:

Tutorial materials:
Tutorial at ESWC 2009: The Web of Data for E-Commerce in One Day: A Hands-on Introduction to the GoodRelations Ontology, RDFa, and Yahoo! SearchMonkey

Received on Monday, 22 June 2009 21:16:52 UTC