My sincere congratulations, i had someone overlooked at this level of detail needed here.
The choices are pragmatic and - in my personal opinion having talked directly at SemTech with a lot of people involved in this - should serve the community as good as possible. will you be posting this as a FAQ i think its definitely worth it. Gio On Sat, Jun 11, 2011 at 6:55 PM, Richard Cyganiak <rich...@cyganiak.de> wrote: > All, > > Thanks for the thoughtful feedback regarding schema.rdfs.org, both here and > off-list. > > This is a collective response to various arguments brought up. I'll > paraphrase the arguments. > >> Limiting ranges of properties to strings is bad because we LD people might >> want to use URIs or blank nodes there. > > Schema.org says the range is a string, and the RDFS translation reflects > this. We tried to formally describe schema.org in RDFS. We did not try to > make a fork that improves upon their modelling. That might be a worthwhile > project too, but a different project. > >> Schema.org documentation explicitly say that you can use a text instead of a >> Thing/Person/other type. > > This is the opposite case from the one above: They say that in place of a > resource, you can always use a text. That's ok—we didn't say that > schema:Thing is disjoint from literals. (I'm tempted to add “xsd:string > rdfs:subClassOf schema:Thing.” to capture this bit of the schema.org > documentation.) > >> The range should use rdfs:Literal instead of xsd:string to allow language >> tags. > > That's a good point. The problem is that xsd:string is too narrow and > rdfs:Literal is too broad. RDF 1.1 is likely to define a class of all string > literals (tagged and untagged), we'll use that when its name has been > settled, and perhaps just leave the inaccurate xsd:string in place for now. > >> You should use owl:allValuesFrom instead of the union domains/ranges. > > Probably correct in terms of good OWL modelling. But the current modelling is > not wrong AFAICT, and it's nicer to use the same construct for single- and > multi-type domains and ranges. > >> Nothing is gained from the range assertions. They should be dropped. > > They capture a part of the schema.org documentation: the “expected type” of > each property. That part of the documentation would be lost. Conversely, > nothing is gained by dropping them. > >> You should jiggle where rdfs:isDefinedBy points to, or use wdrs:describedby. > > > This could probably be done better, but the way we currently do it is simple, > and not wrong, so we're a bit reluctant to change it. > >> You're missing an owl:Class type on the anonymous union classes. > > Good catch, fixed. Thanks Holger! > >> You should add owl:FunctionalProperty for all single-valued properties. > > The schema.org documentation unfortunately doesn't talk about the cardinality > of properties. Using heuristics to determine which properties could be > functional seems a bit risky, given that it's easy to shoot oneself in the > foot with owl:FunctionalProperty. > >> There are UTF-8 encoding problems in comments. > > Fixed. Thanks Aidan! > >> You should mint new URIs and use http://schema.rdfs.org/Thing instead of >> http://schema.org/Thing. > > > Schema.org defines URIs for a set of useful vocabulary terms. The nice thing > about it is that the URIs have Google backing. The Google backing would be > lost by forking with a different set of URIs. > >> You should mint new URIs because the schema.org URIs don't resolve to RDF. > > > Dereferenceability is only a means to an end: establishing identifiers that > are widely understood as denoting a particular thing. Let's acknowledge > reality: Google-backed URIs with HTML-only documentation achieve this better > than researcher-backed URIs which follow best practices to a tee with a > cherry on top. > >> You are violating httpRange-14 because you say that http://schema.org/Thing >> is a class, while it clearly is an information resource. > > Schema.org documentation uses these URIs as classes and properties in RDFa. > They also return 200 from those URIs. So it's them who are violating > httpRange-14, not us. Draw your own conclusion about the viability of > httpRange-14. > >> You should use http://schema.org/Thing#this. > > > Schema.org is using http://schema.org/Thing as a class in their RDFa > documentation. I don't think we should mint different URIs in their namespace. > >> http://schema.org/Person is not the same as foaf:Person; one is a class of >> documents, the other the class of people. > > I don't think that's correct at all. http://schema.org/Person is the class of > people and is equivalent to foaf:Person. It's just that the schema.org > designers don't seem to care much about the distinction between information > resources and angels and pinheads. This is the prevalent attitude outside of > this mailing list and we should come to terms with this. > > Best, > Richard >
