 |
 |
On 10/1/14, 4:21 AM, Bosch, Thomas wrote: > Hi Tom, > > there has been a lot of discussion of this topic on the W3C RDF Validation mailing list, with lot's of pros and cons using OWL and OWL 2 for RDF validation. > > I also see the need for such a requirement. > This requirement is not in the requirements database so far. > > What would be an identifier of such a requirement? > Let me try: > Separate Contraint Semantics and Ontology Semantics How about: Separation of Constraints and Ontology Semantics I think it will need a rather precise definition, and I'm happy to contribute to that. I believe that the bottom line is that the validation constraints must not alter the semantics of the underlying ontology. It's a matter of thinking about both the closed world and the open world at the same time. In fact, I would go so far as to say that "meaning" is entirely the role of RDF/OWL, and that the application profile exercises data creation and management constraints. The things called "constraints" in OWL are actually axioms that permit one to infer meaning from relationships between properties, but do not constrain, in the data quality sense, at all. So it's constraints on the AP side, and semantics on the RDF/OWL side. kc > > Do you have a better one? > > There is a requirements class 'constraint semantics'. > I would assign this requirement to this class. > > We also have requirements which are fairly related: > R-140-SEPARATE-ONTOLOGIES-FROM-VALIDATION-SCHEMAS > R-173-SEPARATE-CONSTRAINTS-FROM-VOCABULARIES-AND-ONTOLOGIES > R-177-DEFINE-SEMANTICS-FOR-CONSTRAINTS > > ----- > regarding the meaning between "domain as a means of enabling inference" (the OWL sense) and "domain as a way to bind properties to classes" > > I think it is important to choose if you want to use reasoning when using OWL for RDF validation. > The RDF validator can be used for RDF validation with and without inferencing. > > > Cheers, > Thomas > > -- > Thomas Bosch, M.Sc. (TUM) > PhD Student > GESIS - Leibniz Institute for the Social Sciences > Social Science Metadata Standards > Visitors Address: B2,1, D-68159 Mannheim > Postal Address: P.O.Box 12 21 55, D-68072 Mannheim > Tel: + 49 (0) 621 / 1246-271 > Fax: + 49 (0) 621 / 1246-100 > Web: http://www.gesis.org > Website: http://boschthomas.blogspot.com/ > GitHub: https://github.com/boschthomas/PhD > > > ________________________________________ > Von: DCMI Architecture Forum [[log in to unmask]]" im Auftrag von "Thomas Baker [[log in to unmask]] > Gesendet: Mittwoch, 1. Oktober 2014 12:34 > An: [log in to unmask] > Betreff: [RDF AP] Re-purposing OWL properties > > On Tue, Sep 30, 2014 at 11:05:08AM -0700, Karen Coyle wrote: >> https://meetings.webex.com/collabs/meetings/playRecording?recordID=12797906&meetingInstanceID=ICWDUC9I93MGCE3CLXLPUZVPSX-JV0D > > I tried to join yesterday -- it was 23:00 here in Seoul -- but couldn't > get a WebEx connection after five attempts. I did however get a chance > to listen to the recording today. I'm sorry I couldn't be there live, > because I'm trying to catch up with the discussion, and apologies in > advance if the points I make have already been discussed and decided. > > Apart from the glitch that addresses do not know people, the DSP demo > was very nice! However, I get very uneasy when I see OWL2 axioms being > treated as "constraints" in a DSP sense (i.e., interpreted according to > CWA). I agree with Karen, if I correctly understood her point, that > this is "dangerous territory". > > On the call, that discussion was postponed for a later date, but I look > forward to having that discussion as soon as possible because I think it > is fundamental. > > As I see it, the whole question of how a constraint language relates to > RDF vocabularies and ontologies is one of the most important and basic > _requirements_ for the constraint language itself. The requirement is > that a constraint language not replace (or "hijack") the original > semantics of properties used in the data. I get uneasy, for example, > when OWL cardinality axioms are treated as "constraints" according to a > closed-world, unique-name assumption, or by using rdfs:domain or range > axioms as if they were expressing mandatory graph patterns. > > In my recollection, the difference in meaning between "domain as a means > of enabling inference" (the OWL sense) and "domain as a way to bind > properties to classes" was a source of confusion when the Schema.org > vocabulary first appeared, because the early, now-deprecated > representations of the Schema.org vocabulary in OWL translated > Schema.org domains as rdfs:domain, whereas the Schema.org data model now > makes clear that a much looser definition is intended -- one that has > more to do with documenting intention than with enabling inference [1]: > > We have a set of properties: > > each property may have one or more types as its domains. The > property may be used for instances of any of these types. > > each property may have one or more types as its ranges. The > value(s) of the property should be instances of at least one > of these types. > > Has it been proposed to express as a requirement, alongside the other > requirements, the notion that the constraint language not impose an > alternative interpretation on existing semantics? > > Tom > > [1] http://wiki.dublincore.org/index.php/RDF-Application-Profiles/ExamplesFormalConstraints#R-25-OBJECT-PROPERTY-DOMAIN > [2] http://schema.org/docs/datamodel.html > > -- > Tom Baker <[log in to unmask]> > -- Karen Coyle [log in to unmask] http://kcoyle.net m: 1-510-435-8234 skype: kcoylenet/+1-510-984-3600