- From: Stephan Zednik <zednis@rpi.edu>
- Date: Wed, 12 Sep 2012 11:29:59 -0600
- To: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- Cc: public-prov-wg@w3.org
On Sep 12, 2012, at 7:22 AM, Luc Moreau <l.moreau@ecs.soton.ac.uk> wrote: > Hi Curt and Stephan, > > I am less certain about this change. > > First, do you mean QName as in xsd:QName? Yes. > Why not use the prov:QualifiedName, which we already have (and can be transformed into uris). We could do that, what is the distinction? I suggested xsd:QName since we were already using it for the id attribute in the XML schema. > > But then, why just prov:QualifiedName , and why not URI (xsd:anyURI)? We use URI's for types in PROV-O so I am not against this. I suggested xsd:QNames since we were already using it with ids, and because it is a currently valid prov:type type since QName is mentioned as a valid value of a DM Value. > > The reason why this was left unspecified is that PROV, intentionally, refrained from defining > what a type system is, and therefore, a consequence, was that we didn't define how to > represent a given type value. Then perhaps the question should be, "How do we define a type system for PROV-XML that makes sense?". I think the type system PROV-O adopted is very good, and the type system the DM defines is too broad. --Stephan > > Luc > > On 09/12/2012 01:27 PM, Curt Tilmes wrote: >> >> I agree with Stephan. The real reason for having prov:type at all is >> to encourage consistency. Qnames encourage capturing semantic meaning >> beyond free text. >> >> The types we've defined >> http://www.w3.org/TR/prov-dm/#term-attribute-type >> set a precedent for the type of types we think should fill prov:type, >> and the discussion of prov:type in the extensibility points section: >> http://www.w3.org/TR/prov-dm/#extensibility-section >> shows examples defining new prov:types as qnames in other namespaces. >> >> This would require some rework of examples, but I think the change >> would be valuable in the long term. >> >> Curt >> >> On 09/12/2012 02:19 AM, Stephan Zednik wrote: >>> A quick reminder about this issue. >>> >>> Looking at the PROV-DM document again I see a few examples where simple >>> non-qname strings are used for prov:type values. >>> >>> From example 21 (http://www.w3.org/TR/prov-dm/#anexample-communication) >>> >>> prov:type="fine paying, check writing, and mailing" >>> >>> I think in most if not all of these cases the prov:type value could be >>> simplified to a qname. >>> >>> I understand this change is significant due to the timing of the >>> suggestion, but I believe the benefit of making this change is worthwhile. >>> >>> Thanks, >>> --Stephan >>> >>> On Sep 4, 2012, at 11:18 AM, Provenance Working Group Issue Tracker >>> <sysbot+tracker@w3.org <mailto:sysbot+tracker@w3.org>> wrote: >>> >>>> PROV-ISSUE-493: prov:type has type Value; valid values too general, >>>> include number, datetime, boolean, etc. [prov-dm] >>>> >>>> http://www.w3.org/2011/prov/track/issues/493 >>>> >>>> Raised by: Stephan Zednik >>>> On product: prov-dm >>>> >>>> The value of prov:type is a Value >>>> (http://www.w3.org/TR/prov-dm/#term-value) which has the following >>>> definition: >>>> >>>> A value ◊ is a constant such as a string, number, time, qualified >>>> name, IRI, and encoded binary data, whose interpretation is outside >>>> the scope of PROV. Values can occur in attribute-value pairs. >>>> >>>> Each kind of such values is called a datatype. Use of the following >>>> data types is recommended. >>>> >>>> The RDF-compatible [RDF-CONCEPTS] types, including those taken from >>>> the set of XML Schema Datatypes [XMLSCHEMA11-2]; >>>> Qualified names introduced in this specification. >>>> The normative definitions of these datatypes are provided by their >>>> respective specifications. >>>> >>>> This means that numbers, datetimes, booleans, and unstructured strings >>>> are valid values of prov:type. The prov value section on RDF >>>> compliance also seems to suggest there should be a prov:type datatype >>>> property in prov-o, which to my knowledge does not currently exist. >>>> >>>> So my question is, are we ok with numbers, datetimes, booleans as >>>> valid values of prov:type? All of the examples in the DM document >>>> appear to use qnames for values of prov:type. >>>> >>>> Second, is there support for a proposal to restrict values of >>>> prov:type to qnames? >>>> >>>> >>>> >>>> >>> >> >> > > -- > Professor Luc Moreau > Electronics and Computer Science tel: +44 23 8059 4487 > University of Southampton fax: +44 23 8059 2865 > Southampton SO17 1BJ email: l.moreau@ecs.soton.ac.uk > United Kingdom http://www.ecs.soton.ac.uk/~lavm > > >
Received on Wednesday, 12 September 2012 17:30:49 UTC