Why xsd:anyURI literals instead of real URLs?

[VladimirAlexiev]

• me (from Suggestions for ONTOLOGY_GUIDE #983 item 17): Please explain why do you use owl:DatatypeProperties with ^^xsd:anyURI instead of real URLs (i.e. owl:ObjectProperties without range).
• @ElisaKendall If you use OWL reasoning, there are certain declarations / uses that disallow a URI in the range. So for annotations we've used anyURI.

Elisa, can you please explain these declarations / uses / restrictions?

• I've wondered for years why people use xsd:anyURI literals instead of real URLs, and haven't found an explanation.
• It's worth explaining it in https://github.com/edmcouncil/fibo/blob/master/ONTOLOGY_GUIDE.md

I analyzed instances of anyURI in 2020Q3-prod like this:

 find . -iname '*.ttl'|xargs cat|riot -syntax ttl -out nt |sort > all.nt
 grep anyURI all.nt |cut -d " " -f2 |sort|uniq -c|sort -rn > anyURI-props.txt

A lot are annotation props but not all. Star indicates maybe a change is needed:

*  1990 <https://spec.edmcouncil.org/fibo/ontology/FND/Places/VirtualPlaces/hasWebsite>
*   571 <http://www.omg.org/techprocess/ab/SpecificationMetadata/dependsOn>
    479 <https://spec.edmcouncil.org/fibo/ontology/FND/Utilities/AnnotationVocabulary/adaptedFrom>
*   130 <http://purl.org/dc/terms/license>
*   122 <http://www.omg.org/techprocess/ab/SpecificationMetadata/contentLanguage>
     41 <https://spec.edmcouncil.org/fibo/ontology/FND/Utilities/AnnotationVocabulary/definitionOrigin>
      4 <http://www.w3.org/2000/01/rdf-schema#seeAlso>
      2 <http://www.w3.org/2000/01/rdf-schema#range>
      1 <https://spec.edmcouncil.org/fibo/ontology/FND/Utilities/AnnotationVocabulary/explanatoryNote>
      1 <http://www.w3.org/2004/02/skos/core#example>
      1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
      1 <http://www.omg.org/techprocess/ab/SpecificationMetadata/relatedSpecification>
      1 <http://www.omg.org/techprocess/ab/SpecificationMetadata/directSource>
?     1 <http://purl.org/dc/terms/source>

I checked range and the list:

 grep anyURI all.nt |grep -E "#range|#first"

The following props have range xsd:anyURI:

• https://spec.edmcouncil.org/fibo/ontology/FND/Places/VirtualPlaces/hasURL
• https://spec.edmcouncil.org/fibo/ontology/FND/Places/VirtualPlaces/hasWebsite
• https://spec.edmcouncil.org/fibo/ontology/FND/Utilities/Analytics/QualifiedMeasure (string or anyURI, see Unexpected triple in 'qualified measure' #933)

[VladimirAlexiev]

Why changes are needed:

A. (from #983 item 18) sm:dependsOn should be an object property since its target is an object (a owl:Ontology). It's bad style to represent the same resource as anyURI literal and as IRI:

	sm:dependsOn
"https://spec.edmcouncil.org/fibo/ontology/FND/Accounting/CurrencyAmount/"^^xsd:anyURI 
	owl:imports
<https://spec.edmcouncil.org/fibo/ontology/master/latest/FND/Accounting/CurrencyAmount/> 

B. contentLanguage uses both of these forms, which is bad:

"http://www.w3.org/standards/techs/owl#w3c_all"^^<http://www.w3.org/2001/XMLSchema#anyURI>
<http://www.w3.org/standards/techs/owl#w3c_all>

C. DCT specifies license range dct:LicenseDocument (an object) and source a rdf:Property (which admits literal or object)

D. hasWebsite and hasURL: If the criterion for using anyURI is "does the target have a type" or "does the target have some statements", that's a very brittle criterion and contradicts OWA.
Eg if I add a type and some statements about a website URL (eg using schema.org), does that mean hasWebsite should become an object property?

[rivettp]

These are all good points except I don't understand D - it seems that these are declared and used as datatype properties with the anyURI datatype. I don't think it makes sense to try to represent sites as resources for FIBO. And if they were separately modeled as resources I don't see that being a problem either.

[VladimirAlexiev]

@rivettp what you describe in D means that FIBO rejects OWA.

• It's ok for FIBO to decide that website info is out of scope of FIBO,
• but it's not ok to select a representation such that nobody can add info about those websites