- From: Bijan Parsia <bparsia@isr.umd.edu>
- Date: Fri, 26 Aug 2005 12:23:13 -0400
- To: Tatiana Vieira <tascvieira@yahoo.com.br>
- Cc: David Martin <martin@AI.SRI.COM>, public-sws-ig@w3.org, chen Xiaoyan <ruppur@hotmail.com>
On Aug 26, 2005, at 12:02 PM, Tatiana Vieira wrote: > Hi people, > > As the topic here is namespace, let me ask a question. If a namespace > isn't necessarily an URL It isn't. See URNs. > (it isn't necessary to be a physical location), how can anyone > discover the concepts declared in an ontology? Ontology != namespace. An ontology (thought of as a logical theory) can have axioms using terms from an arbitrary number of namespaces (actually, there *is no such thing* as a namespace in RDF or OWL; there are only URIs; the closest approximation to a "namespace" is "uris sharing a common prefix"; but note that all http uris share some common prefixes!) Terms can be defined in more than one ontology. > I mean, how can I use a specicified vocabulary defined in any place > in Web if I can't find it? You can find it some other way, e.g., by checking a list, or by being emailed the ontology, etc. It's not *that* hard. > And, also, how can we be sure that namespaces will not conflict, You cannot be sure that people will use the term the same (or in compatible) ways. > I mean, that two diferent users will not put an igual namespace for > different documents? They might even put contradictory axioms for the very same term! (which is more severe, obviously). C'est la vie, eh? The key for a consumer is to determine which documents they trust. Some people take it as a strong rule that you should trust the documents retrievable from the URI owner's server wrt those URIs. Others (like me) are not so restrictive. Cheers, Bijan.
Received on Friday, 26 August 2005 16:23:26 UTC