Re: [DPF] Property Declarations

Greetings Keith, folks monitoring the public editors list will probably 
recognise CC/PP and UAProf but we need to say a little more for them to 
understand CPC -- or whatever its new name is/will be.

Regards, Roland
Tel/Fax: +44 (0)1926-465440



Keith Waters <kwaters@ftrd.us> 
Sent by: www-di-request@w3.org
23/06/2005 14:06

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www-di@w3.org
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Subject
[DPF] Property Declarations







Hi Dan,

This message contains a response to comments on

http://www.w3.org/TR/2004/WD-DPF-20041122/

How do DPF adopters publish and publicise their DPF property 
namespaces? Do you have an mechanism/plans/roadmap to allow 
properties to be documented in some form other than human-oriented 
prose? eg. from B1: DPF.location.format="postal code";

Who defines the property 'location'? In practice, what do they do to 
tell users of the property that it's correct value is an entity that 
has properties such as 'format'. I assume some namespace mechanism 
disambiguates 'location' and 'format' by associating them with URIs, 
but am unclear how this alone is enough to support the loosly- 
coupled, multi-party heterogenous extensibility that DPF seems to aim 
for.

If I'm a DPF adopter and want to publicise a property that applies to 
locations, and I've somehow found the URI for this 'location' 
property, what do I do? Pretend my new property is 
danbri:averageRainfall, and I've a domain name etc etc I can assign 
to it. What can I do, in a machine-readable (and hence more I18N- 
friendly than prose) way to say that my danbri:averageRainfall 
property is intended to apply to the kind of thing that b1:location 
takes as its value? How do we help DPF adopters, many of whom won't 
read English, from mis-using the 'location' property, eg. by using it 
with textual strings values. Can XML schema languages be used 
somehow? RDF/RDFS/OWL? Is new work planned in this area?

This is related to my questions above of course, since RDF/RDFS/OWL 
might serve as an already-existing property declaration mechanism, 
assuming the datamodels match up. But it could well be the case that 
RDF doesn't suit your WG's needs, or even that figuring out whether 
it is usable could be too expensive an undertaking. I intend the 
questions above as small steps towards figuring out how DPF and RDF 
might inter-relate, rather than as evangelism/advocacy to persuade 
you all to "go over to RDF"!

So I should stress that while I'm clearly coming at this problem 
space from the RDF tradition, I don't yet know enough about DPF. 
These are my initial reactions on reading the WD, basically that it 
would be good to be able to consume DPF data in RDF environments, 
since RDF is also based around a hetergenous model for properties. 
And also that there are many RDF-defined properties already in 
existence, some of which might address DPF usage scenarios. I'd like 
to be able to advice RDF and DPF adopters on whether a single 
property URI/namespace can be used, and if not, have some explanation 
to offer them to account for apparent duplication.

Response:

DPF does not of itself define any vocabularies. It relies on other 
specifications, such as CC/PP, UAProf and CPC to provide appropriate 
vocabularies.

-Keith Waters