A property to indicate membership in an ontology appears to be missing from the standard semweb stack. Some folks use rdfs:isDefinedBy to point from resources to an ontology, but rdfs:isDefinedBy is also used for other things. AFAIK there is no inverse-ish property whose domain includes owl:Ontology that can be used to assemble a set of classes and properties to be deemed to be part of the ontology. I sometimes use dct:hasPart but that doesn't seem quite strong or specific enough. Maybe just rdfs:member . Simon -----Original Message----- Date: Thu, 22 Jan 2015 16:35:36 +0100 From: ?amonn ? Tuama [GBIF] <eotuama@gbif.org> Subject: Re: [tdwg-content] Darwin Core Standard - proposed change in governance To: "'Steve Baskauf'" <steve.baskauf@vanderbilt.edu>, "'Tim Robertson'" <trobertson@gbif.org> Cc: 'TDWG Content Mailing List' <tdwg-content@lists.tdwg.org>, '"Markus D?ring (GBIF)"' <mdoering@gbif.org> Message-ID: <00d101d03659$119e2330$34da6990$@org> Content-Type: text/plain; charset="iso-8859-1" Dublin Core tackles the issue of ?borrowing? from other vocabularies through the construct of Dublin Core Application Profiles [1] ? something separate from the specification of DC itself. ?amonn [1] http://dublincore.org/documents/2009/05/18/profile-guidelines/ From: tdwg-content-bounces@lists.tdwg.org [mailto:tdwg-content-bounces@lists.tdwg.org] On Behalf Of Steve Baskauf Sent: 22 January 2015 15:41 To: Tim Robertson Cc: TDWG Content Mailing List; "Markus D?ring (GBIF)" Subject: Re: [tdwg-content] Darwin Core Standard - proposed change in governance I'm not sure whether anyone ever established that there was a consensus on this, but it has been suggested repeatedly that the basic Darwin Core vocabulary should have minimal restrictions and semantics imposed upon it. This allows other layers to be built upon it (XML schemas, RDF-based ontologies, etc.) that are intended to serve more specialized purposes.

From the standpoint of the normative RDF document, that means that it should include very little in the way semantics that would create entailments for semantic clients. That doesn't mean that there is no value in having that RDF, because the resources defined by that document can be nodes that can be linked and restricted by other ontologies. This has been done or is being done by Darwin-SW and BCO, for example.

Having the RDF document contain few machine-interpretable properties is a separate issue from whether it is a good idea for that document to be normative. Bob makes a good point that if it is the normative document yet does not contain the information required for defining how the terms should be used, it may be inadequate. We already have that situation with the Dublin Core terms. Since they are defined as RDF by DCMI, we don't include them in our normative RDF document. So if potential users were to try to use Darwin Core by looking solely at the normative document (which they should be able to do, at least in theory), they would not know that Darwin Core includes Dublin Core terms. This is a point that should be considered in discussions on a TDWG-wide policy on vocabulary documentation. It's an even bigger issue in Audubon Core, since a much higher proportion of its terms are "borrowed" from other vocabularies than DwC. Steve Tim Robertson wrote: Hi all, I don?t think there has ever been any intention for DwC to impose that kind of restriction, regardless of the format chosen for the authoritative version (e.g. be it wiki text, RDF, HTML or PDF). I?d expect a schema to define that restriction (xsd, class definition etc). Is that how others see it? I believe this is what John meant when he wrote the spec [1]: "There is meant to be a clear separation between the terms defined in this standard and the applications that make use of them. For example, though the data types and constraints are not provided in the term definitions, recommendations are made about how to restrict the values where appropriate." Cheers, Tim [1] http://rs.tdwg.org/dwc/index.htm