W3C home > Mailing lists > Public > public-swbp-wg@w3.org > November 2006

Re: Time Ontology in OWL WD published

From: Feng Pan <pan@ISI.EDU>
Date: Tue, 14 Nov 2006 21:39:03 -0800 (PST)
To: Bernard Vatant <bernard.vatant@mondeca.com>
cc: public-swbp-wg@w3.org, Jerry Hobbs <hobbs@ISI.EDU>
Message-ID: <Pine.GSO.4.60.0611142137060.27180@nitro.isi.edu>
Hi Bernard,

Thank you for your comments on the time ontology note.

The semantics and the rules/axioms for the properties are defined formally 
in first-order logic, which can be found in [1,2]. [1] is linked from the 
note. More comments can be added to the OWL code.

As for the domain and range of time:inside, it's in a similiar situation 
as "begins" and "ends", as we have explained and discussed in [3]. To 
conform to OWL convention, we have followed Guus' comments to change 
"begins" to "hasBeginning" and "ends" to "hasEnd". However, if we would 
have to do the same thing for "inside", it would be changed to 
"hasInteriorPoint", but we would rather not to do so.


Feng Pan and Jerry Hobbs

[1] Jerry R. Hobbs and Feng Pan. 2004. An Ontology of Time for the 
Semantic Web. ACM Transactions on Asian Language Processing
(TALIP): Special issue on Temporal Information Processing, Vol. 3, No. 1, 
March 2004, pp. 66-85.

[2] Jerry R. Hobbs. 2004. An OWL Ontology of Time

[3] http://lists.w3.org/Archives/Public/public-swbp-wg/2006May/0064.html

On Fri, 10 Nov 2006, Bernard Vatant wrote:

> Hello all
> Some remarks on the Time Ontology WD I just start to explore.
> I'm much interested by the rich modeling of time:Interval, and singularly the 
> time:ProperInterval, but am puzzled by all those properties having it for 
> both domain and range, without further comments. Unless I miss something, 
> there is no explanation about their specific semantics and intended use, 
> neither inside the RDF file, nor in the presentation document. One can only 
> guess from the URI what is the semantics of intervalMeets vs intervalOverlaps 
> or intervalEquals (the latter I really don't have any guess on what it is 
> intended to convey, certainly equality, but which kind of equality?). And 
> actually, I should not even try to guess, since there should not be any 
> semantics embedded in those URI fragments, right? Are semantics defined in 
> extra documentation. If so, pointers, please!
> How are people supposed to use those properties correctly? I suggest at least 
> some prose should be added either somewhere in the Draft, and/or preferably 
> as comments in the RDF file itself.
> Moreover, maybe I'm wrong, but seems to me those different properties are 
> formally linked to each other by rules, like e.g., the following in SPARQL 
> (if I got intervalOverlaps semantics and SPARQL syntax correctly ...) BTW I 
> find strange that time:inside has domain time:Interval and range 
> time:Instant. One would expect it the other way round ...
> PREFIX time:    <http://www.w3.org/2006/time#>
> CONSTRUCT   { 	?x time:intervalOverlaps ?y }
> WHERE       { 	?y time:hasBeginning ?a.
> 		?y time:hasEnd ?b.
> 		?x time:inside ?a.
> 		?x time:inside ?b.
> 	    } 
> Cheers
> Bernard
> -- 
> *Bernard Vatant
> *Knowledge Engineering
> ----------------------------------------------------
> *Mondeca**
> *3, citÚ Nollez 75018 Paris France
> Web:    www.mondeca.com <http://www.mondeca.com>
> ----------------------------------------------------
> Tel:       +33 (0) 871 488 459
> Mail:     bernard.vatant@mondeca.com <mailto:bernard.vatant@mondeca.com>
> Blog:    Lešons de Choses <http://mondeca.wordpress.com/>

Feng Pan, Ph.D. Candidate
USC Information Sciences Institute (ISI)
Email: pan@isi.edu
Web: http://www.isi.edu/~pan/
Received on Wednesday, 15 November 2006 05:39:38 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:09:47 UTC